WO2021142588A1

WO2021142588A1 - Electro-optical modulator and manufacturing method therefor, and chip

Info

Publication number: WO2021142588A1
Application number: PCT/CN2020/071841
Authority: WO
Inventors: 陈宏民; 孙梦蝶
Original assignee: 华为技术有限公司
Priority date: 2020-01-13
Filing date: 2020-01-13
Publication date: 2021-07-22
Also published as: CN114730106A

Abstract

An electro-optical modulator and a manufacturing method therefor, and a chip. The manufacturing method for the electro-optical modulator comprises: providing a substrate (10), a dielectric layer (100) being formed on the substrate (10), and an input waveguide (112) and an output waveguide (113) being formed in the dielectric layer (100) (S101); bonding an electro-optical crystal film layer (120) on the surface of the dielectric layer (100), the electro-optical modulation efficiency of an electro-optical crystal being higher than the electro-optical modulation efficiency of the input waveguide (112) and the output waveguide (113), the electro-optical crystal film layer (120) comprising a ridge-shaped structure (121) (S102), the ridge-shaped structure (121) comprising an input coupling portion and an output coupling portion, the input coupling portion being used for coupling a signal in alignment with the input waveguide (112) to the ridge-shaped structure (121), and the output coupling portion being used for coupling the signal in the ridge-shaped structure (121) to the output waveguide (113) for alignment; and forming metal electrodes (130) on the surfaces of electro-optical crystals at both sides of the ridge-shaped structure (121) (S103). The electro-optical crystals have high modulation efficiency, and therefore, the electro-optical modulation efficiency is improved, and the manufacturing process of the electro-optical modulator is simplified.

Description

Electro-optical modulator and its manufacturing method and chip

Technical field

This application relates to the field of optical communication technology, and in particular to an electro-optical modulator, a manufacturing method thereof, and a chip.

Background technique

With the development of Internet technology, the demand for information transmission is getting higher and higher. Therefore, the demand for optical links in future data centers and long-distance communication networks is also getting higher and higher. Usually, optical links are required to have ultra-high bandwidth (> 100GHz) modulation, low drive voltage, low loss, small size, low temperature sensitivity, low-cost electro-optical (EO) interface, etc. Among them, electro-optical modulators can load electrical signals onto optical signals as the core interface for realizing the conversion of information from the electrical domain to the optical domain. Its performance directly affects the performance of the optical signal processing system, so it has been receiving wide attention.

In order to implement integrated electro-optic modulators on a chip, electro-optic modulators using standardized silicon-based integrated processes have emerged. Doped silicon is used as a light guide medium. The effective refractive index of the doped silicon waveguide can be changed through the control of electrodes. The phase modulation of the signal in the silicon waveguide is completed, or the silicon waveguide can form a two-arm interference structure, and then the phase modulation is converted into intensity modulation. However, the half-wave voltage of doped silicon is relatively high, so it has low modulation efficiency, which is not conducive to obtaining a small-sized electro-optic modulator.

Summary of the invention

In view of this, the first aspect of the present application provides an electro-optical modulator, a manufacturing method thereof, and a chip, which improve the modulation efficiency of the electro-optical modulator.

The first aspect of the embodiments of the present application provides a method for manufacturing an electro-optical modulator. Specifically, a substrate may be provided, and a dielectric layer is formed on the substrate, and an input waveguide and an output waveguide are formed in the dielectric layer. The waveguide can be used to input the signal before modulation, the output waveguide can be used to output the modulated signal, and then the electro-optic crystal film layer can be bonded on the surface of the dielectric layer. The bonded electro-optic crystal film layer includes a ridge structure, and the ridge shape The electro-optical modulation efficiency of the structure is higher than that of the input waveguide and the output waveguide. The ridge structure includes an input coupling part and an output coupling part. The input coupling part is used to couple the signal in the input waveguide to the ridge structure, and the output coupling part is used The signal in the ridge structure is coupled to the output waveguide, and metal electrodes are formed on the surface of the electro-optic crystal film on both sides of the ridge structure.

In this way, the signal in the input waveguide can be coupled to the ridge structure through the input coupling waveguide, and the metal electrodes on both sides of the ridge structure can provide a modulation signal. The refractive index in the ridge structure is changed to modulate the signal, and then the signal is modulated through the output coupling. Part of the modulated signal is coupled to the output waveguide and output. In the embodiments of this application, the input waveguide and the output waveguide can be used to input and output signals, and the input signal can be modulated by the ridge structure, and the ridge structure has higher electro-optical modulation efficiency, so the entire electro-optical modulator is modulated The efficiency is high, and the modulated signal can be coupled to the output waveguide, so that signal transmission and modulation can be realized without adding additional components. At the same time, the embodiment of the present application combines the high modulation efficiency of the electro-optic crystal film layer and the easy engraving of other waveguides. The advantage of etching is that there is no need to etch the electro-optic crystal film to obtain a passive waveguide structure with strict design and etching process requirements, avoiding the complicated process problems caused by a large number of etching of the electro-optic crystal film, and simplifying the electro-optic modulator. The manufacturing process improves the modulation efficiency of the electro-optic modulator.

In some possible implementations, bonding an electro-optic crystal film layer on the surface of the dielectric layer may be specifically bonding an electro-optic crystal structure on the surface of the dielectric layer, wherein the electro-optic crystal structure includes an electro-optic crystal base structure and includes a doped The electro-optic crystal film layer of the element, the electro-optic crystal film layer faces the dielectric layer, and then the substrate structure of the electro-optic crystal is removed by heating to obtain the electro-optic crystal film layer bonded on the surface of the dielectric layer, and then the electro-optic crystal film layer is etched to form a ridge structure .

In the embodiments of this application, the electro-optic crystal film layer can be bonded to the surface of the dielectric layer by doping in the electro-optic crystal body structure. The bonding process is simple and easy to operate. At the same time, the thickness and doping of the electro-optic crystal film layer Miscellaneous processes are related and easy to control, thus simplifying the manufacturing process.

In some possible implementation manners, the material of the electro-optic crystal film layer may be lithium niobate, indium phosphide, or tantalum niobate.

In some possible implementations, metal electrodes are formed on both sides of the ridge structure on the surface of the electro-optic crystal film layer. Specifically, a transparent conductive layer is formed on both sides of the ridge structure on the surface of the electro-optic crystal film layer. A metal electrode is formed, and the lateral distance between the transparent conductive layer and the ridge structure is smaller than the lateral distance between the metal electrode and the ridge structure.

In the embodiments of the present application, a transparent conductive layer can also be formed between the electro-optic crystal film layer and the metal electrode. Since the transparent conductive layer absorbs light signals weakly, it causes less light loss. Therefore, compared with the metal electrode In other words, the transparent conductive layer can have a smaller lateral distance from the ridge structure, which increases the electric field of the ridge structure to a certain extent, and improves the efficiency of electro-optic modulation.

In some possible implementations, the input waveguide and output waveguide may be silicon or silicon nitride.

In some possible implementations, the dielectric layer also includes a first optical splitter connected to the input ends of the two input waveguides, and a second optical splitter connected to the output ends of the two output waveguides, and the electro-optic crystal film layer There are two ridge structures, and each ridge structure is respectively coupled with an input waveguide and an output waveguide to realize signal coupling.

In the embodiment of this application, two input waveguides and two output waveguides can be set, and two ridge structures corresponding to them can be set. The input ends of the two input waveguides can be connected to the first optical splitter, and the output of the two output waveguides The end can be connected to the second optical splitter, the signals in the two input waveguides can be separated by the first optical splitter, and the modulated signal can be superimposed together by the second optical splitter connected to the output waveguide, so that the light The phase modulation of the signal is transformed into intensity modulation, which enhances the diversity of electro-optic modulation.

In some possible implementation manners, the metal electrodes shared between the two ridge structures are signal electrodes, and the two metal electrodes respectively disposed outside the two ridge structures are ground electrodes.

In the embodiment of the present application, in the case of multiple ridge structures, metal electrodes can be shared, thereby reducing material waste and simplifying the manufacturing process.

In some possible implementation manners, the method may further include: forming an insulating layer between the ridge structure and the metal electrode.

In the embodiment of the present application, an insulating layer can be formed between the ridge structure and the metal electrode, so that the distance between the ridge structure and the metal electrode can be ensured, and the absorption of the optical signal in the ridge structure by the metal electrode can be reduced.

In some possible implementations, the method may further include: forming other devices on the substrate in areas other than the electro-optic modulator. The other devices may be at least one of a laser diode, a semiconductor optical amplifier, and a photodetector. The laser diode is used to generate the optical carrier, the electro-optical modulator is used to modulate the electrical signal on the metal electrode to the optical carrier to form the optical signal, the semiconductor optical amplifier is used to amplify the optical carrier and/or the optical signal, and the photodetector is used For detecting optical carrier and/or optical signal.

In the embodiments of the present application, the optoelectronic modulator can also be integrated with other devices, so that the integration degree of the chip can be improved and the size of the device can be reduced.

The embodiment of the present application also provides an electro-optical modulator, including: a substrate; a dielectric layer disposed on the substrate; the dielectric layer includes an input waveguide and an output waveguide; an electro-optical crystal film layer disposed on the dielectric layer and Bonded with the surface of the dielectric layer; the electro-optic crystal film layer includes a ridge structure, the electro-optic modulation efficiency of the ridge structure is higher than that of the input waveguide and the output waveguide; the ridge structure includes an input coupling part and an output coupling part; input coupling The part is used to couple the signal in the input waveguide to the ridge structure, and the output coupling part is used to couple the signal in the ridge structure to the output waveguide; the metal electrode is arranged on the surface of the electro-optic crystal layer and is located on both sides of the ridge structure .

In this way, with the electro-optical modulator, the signal in the input waveguide can be coupled to the ridge structure through the input coupling waveguide, and the metal electrodes on both sides of the ridge structure can provide modulated signals, changing the refractive index in the ridge structure to perform the signal processing. Modulate, and then couple the modulated signal to the output waveguide and output through the output coupling part. In the electro-optical modulator, the input waveguide and the output waveguide can be used to input and output signals, and the input signal can be modulated by the ridge structure, and the ridge structure has higher electro-optical modulation efficiency, so the modulation of the entire electro-optical modulator High efficiency, the modulated signal can be coupled to the output waveguide, so that the signal transmission and modulation can be realized without adding additional components. At the same time, the electro-optic modulator combines the high modulation efficiency of the electro-optic crystal film and the easy engraving of other waveguides. The advantage of etching is that there is no need to etch the electro-optic crystal film to obtain a passive waveguide structure with strict design and etching process requirements. This avoids the complicated process caused by a large number of etchings on the electro-optic crystal film during the formation process. The manufacturing process is simplified, and the modulation efficiency of the electro-optic modulator is improved.

In some possible implementations, the electro-optic crystal film layer includes doping elements.

In the embodiments of the present application, the doping elements in the electro-optic crystal film layer can make the electro-optic crystal film layer and the undoped electro-optic crystal have a different lattice structure, which facilitates the bonding of the electro-optic crystal film layer and the dielectric layer.

In some possible implementations, the electro-optic modulator further includes: a transparent conductive layer, which is disposed between the electro-optic crystal film layer on both sides of the ridge structure and the metal electrode; the lateral distance between the transparent conductive layer and the ridge structure is smaller than that of the metal electrode. The lateral distance between the electrode and the ridge structure.

In the embodiments of the present application, a transparent conductive layer can also be formed between the electro-optic crystal film layer and the metal electrode. Since the transparent conductive layer absorbs light signals weakly, it causes less light loss. Therefore, compared with metal electrodes The transparent conductive layer can have a smaller lateral distance from the ridge structure, which increases the electric field of the ridge structure to a certain extent, and improves the efficiency of electro-optic modulation.

In some possible implementations, the electro-optic modulator further includes: a first optical splitter, which is arranged in the dielectric layer and connected to the input ends of the two input waveguides; a second optical splitter, which is arranged in the dielectric layer and is connected to the two The output ends of the output waveguides are connected; the electro-optic crystal film layer has two ridge structures, and each ridge structure is respectively coupled with an input waveguide and an output waveguide to realize signal coupling.

In the embodiment of the present application, the electro-optical modulator may include two input waveguides and two output waveguides, and two corresponding ridge structures. The input ends of the two input waveguides may be connected to the first optical splitter, and the two output waveguides may be connected to the first optical splitter. The output end of the waveguide can be connected to the second optical splitter, so that the signals in the two input waveguides can be separated by the first optical splitter, and the modulated signal can be superimposed together by the second optical splitter connected to the output waveguide. The phase modulation of the optical signal is converted into intensity modulation, which enhances the diversity of electro-optical modulation.

In some possible implementation manners, the metal electrode includes a signal electrode and two ground electrodes, the signal electrode is arranged between the two ridge structures, and the two ground electrodes are respectively arranged outside the two ridge structures.

In the embodiment of the present application, in the case of two ridge structures, the metal electrode can be arranged between the ridge structures, so that the two ridge structures share the metal electrode, which reduces the waste of materials and simplifies the manufacturing process.

In some possible implementation manners, the electro-optic modulator further includes: an insulating layer disposed between the ridge structure and the metal electrode.

The embodiment of the present application also provides a chip that includes at least one of a laser diode, a semiconductor optical amplifier, and a photodetector, and the aforementioned electro-optical modulator; wherein the laser diode is used to generate an optical carrier; the electro-optical modulator is used It is used to modulate the electrical signal on the metal electrode to the optical carrier to form an optical signal; the semiconductor optical amplifier is used to amplify the optical carrier or optical signal; the photodetector is used to detect the optical carrier or optical signal.

In the embodiments of the present application, the optoelectronic modulator and other devices can be integrated to form an integrated chip, which can improve the integration level of the chip and help reduce the size of the device.

Compared with the prior art, this application has the following beneficial effects:

Based on the above technical solutions, the present application provides an electro-optical modulator, a manufacturing method thereof, and a chip. The method includes providing a substrate, a dielectric layer is formed on the substrate, and an input waveguide and an output waveguide are formed in the dielectric layer. The electro-optical crystal film layer is bonded on the surface of the dielectric layer. The electro-optical crystal film layer includes a ridge structure. The electro-optical modulation efficiency of the ridge structure is higher than that of the input waveguide and the output waveguide. The ridge structure may include an input coupling part and an output Coupling part, the input coupling part is used to couple the signal aligned with the input waveguide to the ridge structure, and the output coupling part and part are used to couple the signal in the ridge structure to the output waveguide alignment, on the surface of the electro-optic crystal film layer Metal electrodes are formed on both sides of the upper ridge structure. In this way, the light in the first input waveguide can be coupled to the ridge structure through the input coupling part. When there is a modulation signal in the metal electrode, the refractive index in the ridge structure can be changed to modulate the signal therein. The light coupled to the output waveguide in the output coupling part of the structure is modulated, and the electro-optic crystal has a higher modulation efficiency, so the efficiency of the electro-optic modulation is improved. At the same time, the embodiment of the application combines the electro-optic crystal film layer and other waveguides. The advantage of this method is that there is no need to etch the electro-optic crystal film to obtain a passive waveguide structure with strict design and etching process requirements, thus avoiding the complicated process problems caused by a large number of etching of the electro-optic crystal film and simplifying the manufacturing process.

Description of the drawings

In order to clearly understand the specific embodiments of the present application, the following briefly describes the drawings used in describing the specific embodiments of the present application. Obviously, these drawings are only part of the embodiments of the present application.

FIG. 1 is a flowchart of a manufacturing method of an electro-optic modulator provided by an embodiment of the application;

2 is a schematic diagram of an electro-optical modulator in the manufacturing process of the electro-optical modulator in an embodiment of the application;

3 is a schematic diagram of another electro-optical modulator in the manufacturing process of the electro-optical modulator in an embodiment of the application;

4 is a schematic diagram of still another electro-optical modulator in the manufacturing process of the electro-optical modulator in an embodiment of the application;

FIG. 5 is a schematic diagram of another electro-optical modulator in the manufacturing process of the electro-optical modulator in an embodiment of the application;

6 is a schematic diagram of still another electro-optical modulator in the manufacturing process of the electro-optical modulator in an embodiment of the application;

FIG. 7 is a schematic diagram of still another electro-optical modulator in the manufacturing process of the electro-optical modulator in an embodiment of the application;

FIG. 8 is a schematic diagram of another electro-optical modulator in the manufacturing process of the electro-optical modulator in an embodiment of the application;

FIG. 9 is a schematic diagram of still another electro-optical modulator in the manufacturing process of the electro-optical modulator in an embodiment of the application;

FIG. 10 is a schematic diagram of a device structure of an integrated chip provided by an embodiment of the application;

FIG. 11 is a schematic diagram of a device structure of another integrated chip provided by an embodiment of the application.

Detailed ways

In view of this, the present application provides an electro-optic modulator and a manufacturing method and chip thereof to improve the modulation efficiency of the electro-optic modulator.

In order to understand the specific implementation of the present application more clearly, the electro-optic modulator provided in the present application will be described in detail below with reference to the accompanying drawings.

Referring to FIG. 1, it is a flowchart of a method for manufacturing an electro-optic modulator according to an embodiment of this application, and FIGS. 2-9 show the electro-optic modulator in the manufacturing process of the electro-optic modulator in the embodiment of the application. Schematic diagram, the method can include the following steps:

S101, a substrate 10 is provided, a dielectric layer 100 is formed on the substrate, and an input waveguide 112 and an output waveguide 113 are formed in the dielectric layer 100, as shown in FIG. 2 and FIG. 3.

In the embodiment of the present application, the substrate 10 can be used as a supporting member for subsequent devices, and can be a Si substrate, a Ge substrate, a SiGe substrate, etc., and a substrate of other elemental semiconductors or compound semiconductors, such as GaAs, InP, or SiC, etc. It can also be a laminated structure, such as Si/SiGe. In this embodiment, the substrate 10 is a bulk silicon substrate, specifically high-resistance silicon.

A dielectric layer 100 may be formed on the substrate 10, and the dielectric layer 100 may provide a confinement effect for the light in the optical waveguide therein. Specifically, the dielectric layer 100 may be silicon oxide, silicon nitride, or the like. In actual operation, an oxidation process may be performed on the substrate to form a silicon oxide film as the lower cladding layer of the optical waveguide. Refer to Figure 2(a), where Figure 2(a) is a top view of the electro-optic modulator, Figure 2(b) is a cross-sectional view of the electro-optic modulator in Figure 2(a) in the AA direction, and Figure 2(c) is The cross-sectional view of the electro-optical modulator in Fig. 2(a) in the BB direction.

The optical waveguide in the dielectric layer 100 may include an input waveguide 112 and an output waveguide 113. The input waveguide 112 and the output waveguide 113 may be silicon material or silicon nitride. It should be noted that in order to distinguish the dielectric layer 100, the input waveguide 112 and the output waveguide 113. When the dielectric layer 100 is silicon nitride, the input waveguide 112 and the output waveguide 113 are silicon materials. The shape of the input waveguide 112 and the output waveguide 113 can be determined according to the actual situation. The input waveguide 112 and the output waveguide 113 can be discontinuous, they can be in the same plane with the same height in the dielectric layer, and the two can be on the same straight line. For example, in the extension direction of the incident end 110 and the exit end 115 of the photoelectric modulator, the optical signal can be incident from the incident end 110 to the input waveguide 112, and the optical signal in the output waveguide 113 can be from The output waveguide 113 exits.

In the scenario where the optical signal in a single waveguide is phase modulated, an electro-optic modulator may include an input waveguide 112 and an output waveguide 113; in the scenario where the optical signal is intensity modulated by two arms forming an interference structure, one The electro-optical modulator may include two input waveguides 112 and two output waveguides 113, wherein the input ends of the two input waveguides 112 are connected to the first beam splitter 111, so that the incident light is evenly divided into two beams and enters the two input waveguides 112 respectively. , And the output ends of the two output waveguides 113 are connected with a second optical splitter 114 to combine the optical signals into a beam of light to obtain the modulated light after interference, which is emitted from the output end 115. Wherein, the first beam splitter 111 and the second beam splitter 114 may be a multimode interferometer structure or an evanescent wave splitting structure.

That is to say, in addition to the input waveguide 112 and the output waveguide 113, other waveguides may be formed in the dielectric layer 100, the other waveguides may include the first optical splitter 111 and the second optical splitter 114, and the other waveguides may also include connecting waveguides, multiple Passive waveguides such as mode interference couplers, polarization beam splitters, polarization conversion waveguides, input terminals 110 and output terminals 115. Other waveguides can be formed on the same layer as the input waveguide 112 and the output waveguide 113. The material of these waveguides can be the same as the material of the input waveguide 112 and the output waveguide 113. In this way, while the input waveguide 112 and the output waveguide 113 are formed, other waveguides can also be formed. Waveguide to meet other connection requirements of the electro-optic modulator. Specifically, the waveguide material can be deposited and etched to form the input waveguide 112, the output waveguide 113, the first beam splitter 111, the second beam splitter 114, the input terminal 110, the output terminal 115, the connecting waveguide, and others. The shape of the desired waveguide.

As an example, the dielectric layer 100 may include a connecting waveguide, and the first beam splitter 111 or the second beam splitter 114 may be connected to a laser diode (LD), a semiconductor optical amplifier (semiconductor optical amplifier, SOA), or the like through the connecting waveguide. Photodetector (photodetector, PD), etc., to achieve a more complex large-scale hybrid monolithic integrated coherent transmitter and receiver (integrated coherent transmitter and receiver, ICTR) optical chip. Among them, the laser diode can be used to generate the optical carrier, the electro-optical modulator can modulate the electrical signal on the metal electrode into the optical carrier to form the optical signal, and the semiconductor optical amplifier can be used to amplify the optical carrier and/or the optical signal. The photodetector can detect the optical carrier and/or the optical signal.

In the embodiment of the present application, the input waveguide 112 and the output waveguide 113 may be covered by the dielectric layer 100. Specifically, after the input waveguide 112 and the output waveguide 113 are formed, the dielectric layer 100 may be deposited thereon to cover the input waveguide 112 and the output waveguide 113. Waveguide 113. Thereafter, the dielectric layer 100 covering the input waveguide 112 and the output waveguide 113 can also be planarized to obtain a smooth surface of the dielectric layer 100. Refer to Figure 3(a), where Figure 3(a) is a top view of the electro-optic modulator, Figure 3(b) is a cross-sectional view of the electro-optic modulator in Figure 3(a) in the AA direction, and Figure 3(c) is The cross-sectional view of the electro-optic modulator in Fig. 3(a) in the BB direction.

Taking the dielectric layer 100 as silicon oxide as an example, after forming the input waveguide 112 and the output waveguide 113, plasma enhanced chemical vapor deposition (PECVD) using a tetraethyl orthosilicate (TEOS) source can be used. Way to deposit silicon oxide.

The silicon substrate with the dielectric layer 100 formed in the embodiment of the application is a typical silicon-on-insulator (SOI) structure in the field. The SOI optical waveguide technology has excellent optical performance and can It is fully compatible with the mature silicon-based complementary metal oxide semiconductor (CMOS) process. Therefore, integrating the optoelectronic modulator on the SOI platform can improve the optical performance while also increasing the chip integration.

S102, bonding an electro-optic crystal film 120 on the surface of the dielectric layer 100. The electro-optic crystal film 120 includes a ridge structure 121, as shown in FIG. 4, FIG. 5, and FIG.

In the embodiment of the present application, an electro-optic crystal film 120 may be bonded on the surface of the dielectric layer 100. The electro-optic crystal film may be thin film lithium niobate (TFLN), indium phosphide (InP), or The film layer of materials such as tantalum niobate, take lithium niobate as an example. The material of lithium niobate is relatively hard. Etching the wafer-level lithium niobate alone to obtain a passive waveguide will cause the process to be too complicated, and bonding is used. In this way, the silicon waveguide and the lithium niobate waveguide can be combined, or the silicon nitride waveguide and the lithium niobate waveguide can be combined, which avoids the process difficulty of a large amount of etching of the lithium niobate film to form a passive waveguide. . At the same time, no adhesive is used in the bonding process, which improves the stability of the connection.

Before bonding the electro-optic crystal film layer 120, an electro-optic crystal body structure can be provided, and the surface of the electro-optic crystal body structure can be doped, for example, helium ion doping, hydrogen ion doping, nitrogen ion doping, etc., the thickness of the doping It can be determined according to the thickness of the electro-optic crystal film layer required. Specifically, the electro-optic crystal body structure can be doped by ion implantation, so that the electro-optic crystal base structure 122 and the electro-optic crystal film layer 120 including doping elements are obtained. The structure of the electro-optic crystal. After that, the surface of the doped electro-optic crystal structure can be planarized to obtain a smooth surface of the electro-optic crystal film 120.

Prior to this, the surface of the dielectric layer 100 can be planarized to obtain a smooth surface of the dielectric layer 100, so that the smooth surface of the dielectric layer 100 and the surface of the electro-optic crystal film 120 can be relatively bonded, wherein, Bonding refers to the combination of two pieces of homogeneous or heterogeneous semiconductor materials with clean surface and atomic level flat surface cleaning and activity treatment, and direct bonding under certain conditions, through van der Waals force, molecular force or even atomic force to make the wafer bond into one body. Technology. After the dielectric layer 100 and the electro-optic crystal film layer 120 are bonded, there is a base structure 122 on the doped electro-optic crystal film layer 120. Refer to FIG. 4, where FIG. 4(a) is a top view of the electro-optic modulator. 4(b) is a cross-sectional view of the electro-optical modulator in FIG. 4(a) in the AA direction, and FIG. 4(c) is a cross-sectional view of the electro-optical modulator in FIG. 4(a) in the BB direction.

After the base structure 122 is removed, the electro-optic crystal film 120 on the dielectric layer 100 may be formed. The method of removing the base structure 122 can be by heating. Since the doped electro-optic crystal film 120 and the base structure 122 have different lattice structures, there is lattice damage in the plane at the boundary of the two during the heating process. , The doped electro-optic crystal film 120 is detached from the base structure 122 and fixed on the surface of the dielectric layer 100. Refer to Figure 5, where Figure 5 (a) is a top view of the electro-optic modulator, Figure 5 (b) is a cross-sectional view of the electro-optic modulator in Figure 5 (a) in the AA direction, and Figure 5 (c) is Figure 5 ( a) A cross-sectional view of the electro-optic modulator in the BB direction. That is to say, the thickness of the electro-optic crystal film 120 finally formed on the dielectric layer 100 depends on the parameters of the doping process, so the electro-optic crystal film 120 with adjustable thickness can be obtained.

After bonding the electro-optic crystal film 120 on the dielectric layer 100, the electro-optic crystal film 120 can be etched to obtain the ridge structure 121 on the electro-optic crystal film 120, which is used to enhance the light confinement during light guiding. Refer to Figure 6, where Figure 6 (a) is a top view of the electro-optic modulator, Figure 6 (b) is a cross-sectional view of the electro-optic modulator in Figure 6 (a) in the AA direction, and Figure 6 (c) is Figure 6 ( a) A cross-sectional view of the electro-optic modulator in the BB direction. In order to improve the electro-optical modulation efficiency of the device, in the embodiments of the present application, the electro-optical modulation efficiency of the ridge structure 121 in the electro-optical crystal film layer can be higher than that of the input waveguide and the output waveguide by selecting the material of the electro-optical crystal. For example, the half-wave voltage of the electro-optical modulation of the ridge structure of lithium niobate is smaller than the half-wave voltage of the electro-optical modulation of the silicon waveguide or the silicon nitride waveguide.

The ridge structure 121 may include an input coupling part and an output coupling part, wherein the input coupling part can be aligned with the input waveguide 112 in the longitudinal direction, so that the signal in the input waveguide 112 can be coupled to the ridge structure through the input coupling part, and the output coupling The part can be aligned with the output waveguide 113 in the longitudinal direction, so that the signal in the ridge structure can be coupled to the output waveguide 113 through the output coupling part. That is, the signal in the input waveguide 112 can be coupled to the input coupling part in the ridge structure 121 to be transmitted in the ridge structure 121, and then the signal is coupled to the output waveguide 113 through the output coupling part for continued transmission (refer to 6(b) and 6(c) in the direction of the dashed arrow), for example, it is transmitted to other devices integrated with the photoelectric modulator on the same substrate.

The coupling between the input coupling part and the input waveguide 112 can be realized by the evanescent wave of the wedge coupler, that is, the area of the input coupling part on the horizontal plane can be smaller than the horizontal area of the input waveguide 112, and the output coupling part and the output waveguide 113 The inter-coupling mode can also be evanescent wave coupling, that is, the area of the output waveguide 113 on the horizontal plane can be smaller than the horizontal area of the output coupling part, so that the signal is smoothly coupled, and the light beam can be transmitted without increasing the volume of the device.

Since the ridge structure 121 is used to connect the input waveguide 112 and the output waveguide 113, its extension direction can be the connection direction between the output end of the input waveguide 112 and the input end of the output waveguide 113. Based on different electro-optic modulators, there can be different numbers of ridge structures 121. In the scenario where the optical signal in a single waveguide is phase modulated, an electro-optic modulator can include an input waveguide 112 and an output waveguide 113. In this case, A ridge structure 121 can be provided; in a scenario where two arms form an interference structure to modulate the intensity of an optical signal, an electro-optic modulator can include two input waveguides 113 and two output waveguides 113, in which case two The ridge structures 121 are arranged in parallel, the input coupling part of each ridge structure 121 is aligned with one input waveguide 112, and the output coupling part is aligned with one output waveguide 113, so as to modulate the signals in the two optical paths.

S103, forming metal electrodes 130 on the surface of the electro-optic crystal film 120 on both sides of the ridge structure 121, as shown in FIG. 7, FIG. 8, and FIG. 9.

In the embodiment of the present application, metal electrodes 130 can be formed on the surface of the electro-optic crystal film 120 on both sides of the ridge structure 121. Specifically, a layer of metal can be deposited, and the excess metal can be removed by etching, leaving the metal electrode 130 and the metal wires connected to the outside world. One of the metal electrodes 130 on both sides of the ridge structure 121 can be applied as a signal electrode, and the other can be used as a ground electrode, so that there is a certain amount on both sides of the ridge structure 121. Voltage difference, thereby adjusting the refractive index in the ridge structure. A radio frequency (RF) signal can be applied to the signal electrode.

For electro-optical crystal materials, based on the Pockels effect, the larger the electric field applied to the optical field area, the stronger the electro-optical effect and the stronger the corresponding phase modulation. Therefore, the metal electrodes 130 on both sides of the ridge structure 121 can be A certain electric field is provided for the ridge structure 121, so that the refractive index in the ridge structure 121 changes with the change of the voltage, and the phase modulation of the optical signal in the ridge structure 121 is realized.

Specifically, in a scenario where the optical signal in a single waveguide is phase-modulated, one electro-optical modulator can be provided with a ridge structure 121, so that two metal electrodes 130 can be provided on both sides of the ridge structure 121, one of which can be The applied voltage serves as a signal electrode, and the other can serve as a ground electrode.

Specifically, in the scene where the interference structure is formed by two arms to modulate the intensity of the optical signal, two parallel ridge structures 121 can be provided, so that three metal electrodes 130 can be provided, and the ridge structures 121 can be provided. For the common signal electrode, two ground electrodes are respectively arranged on the outer side of the ridge structure 121, and the voltage difference between the two sides of the ridge structure 121 can also be realized. Refer to FIG. 7, where FIG. 7(a) is a top view of the electro-optic modulator, and FIG. 7(b) is a cross-sectional view of the electro-optic modulator in FIG. 7(a) along the AA direction. At this time, the two ridge structures 121 are applied with opposite voltages, so their phases are modulated in opposite directions. The final phase difference is double the phase modulated by a single modulator, which improves the modulation efficiency. Optical signals with phase difference can interfere after being merged, and their intensity is determined by the magnitude of the phase difference, so the phase modulation can be converted into modulation.

It can be seen that reducing the distance between the metal electrodes 130 can increase the electric field in the ridge structure 121, thereby improving the modulation efficiency. However, as the distance between the metal electrodes 130 decreases, the metal electrodes 130 absorb light. It is also enhanced, which will cause loss of the optical signal in the ridge structure 121. Therefore, it is necessary to maintain a certain distance between the metal electrode 130 and the ridge structure 121, such as the distance between the metal electrodes 130 on both sides of the ridge structure 121. Is d ₁ , and the dimension of the ridge structure in the direction perpendicular to its extending direction is d ₂ , and d _{2 is} smaller than d ₁ . As an example, the metal electrode may be gold (Au), d ₁ may be 3.5 _{um, and d 2} may be 0.9 um.

In the embodiment of the present application, a transparent conductive layer 140 may be provided between the metal electrode 130 and the ridge structure 121. Specifically, the transparent conductive layer 140 may be formed on the electro-optic crystal film layer 120 on both sides of the ridge structure 121, and then A metal electrode 130 is formed on the transparent conductive layer 140, wherein the distance between the transparent conductive layer 140 and the ridge structure 121 is smaller than the distance between the metal electrode 130 and the ridge structure 121, because the transparent conductive layer 140 absorbs more light signals. Weak, cause less optical loss, and can increase the electric field in the ridge structure 121 to a certain extent, reduce the half-wave voltage, and improve the modulation efficiency. Therefore, it balances the optical loss considering the modulation efficiency and realizes the overall electro-optical modulation. optimization.

The transparent conductive layer 140 may be a transparent conductive oxide (transparent conducting oxides, TCO) layer, for example, indium tin oxide (ITO) or the like.

Since the transparent conductive layer 140 absorbs less light signals, the transparent conductive layer 140 can be closer to the ridge structure 121, and can even be in contact with the ridge structure 121, that is, the transparent conductive layer on both sides of the ridge structure 121 The distance between the layers 140 may be slightly greater than or even equal to the size of the ridge structure 121 perpendicular to its extension direction, that is, the distance between the transparent conductive layers may be d ₃ (d3 is greater than or equal to d2, and smaller than d1), because _{Compared with the distance d 1} between the metal electrodes 130, the distance d ₃ is smaller, so a smaller distance between the electrodes can be obtained, so that the electric field in the ridge structure 121 is improved, and the modulation efficiency is improved. As an example, after the transparent conductive layer 140 is added, the distance between the electrodes is reduced from 3.5um to 0.9um, so that the electro-optical modulation efficiency achieved by the ridge structure 121 of the same size is increased by 7.5 times, which is beneficial to improve the electro-optical Modulation efficiency and reducing the size of electro-optic modulators.

Afterwards, in order to improve the reliability between the metal electrode 130 and the ridge structure 121, an insulating layer may be formed between the metal electrode 130 and the ridge structure 121. The insulating layer may be a light-transmitting material or an opaque material. . In this embodiment, it is specifically silicon oxide. In the embodiments of the present application, since the electro-optic modulator is formed on the SOI platform, the integrated formation of the SOI platform can also be used to form other devices on the substrate except for the electro-optic modulator to realize the electro-optic modulator and The integration of other devices, specifically, the electro-optic crystal film layer in other areas can be etched and removed, and other devices can be formed. The materials of other devices can be bonded to the substrate, or can be formed on the substrate by deposition or other methods. Other devices can be connected to the electro-optic modulator through connecting waveguides.

Other devices can be at least one of laser diodes, semiconductor optical amplifiers, and photodetectors. It is understandable that there can be multiple devices of one type on the same substrate, and each device can be connected in any desired connection sequence. . Referring to FIG. 10, a schematic diagram of the device structure of an integrated chip provided by this embodiment of the application. A laser diode, an electro-optic modulator, and an SOA can be sequentially formed on a substrate. In this way, the laser diode can generate an optical carrier, and the electro-optic modulator can The optical carrier is modulated to form an optical signal, and the SOA can discharge the optical signal; or a laser diode, SOA, and an electro-optic modulator can be formed on the substrate in sequence, so that the SOA can amplify the optical carrier generated by the laser diode, and the electro-optic The modulator can modulate the amplified optical carrier to obtain an optical signal; or a micro photodetector, a laser diode, an SOA, and an electro-optical debugger can be formed on the substrate in sequence, so that the micro photodetector can perform the optical carrier generated by the laser diode. For detection, SOA can amplify the optical carrier generated by the laser diode, and the electro-optical modulator can modulate the amplified optical carrier to obtain an optical signal.

It should be noted that the above is only an example of an integrated chip, and those skilled in the art can form other combinations of the above-mentioned electro-optical modulator and other devices according to actual conditions, which will not be illustrated here.

Referring to FIG. 11, there is a schematic diagram of the device structure of another integrated chip provided by this embodiment of the application. The electro-optic modulator formed by the above method and the photodetector 20 can be formed on the substrate, wherein the photodetector 20 can pass through The connecting waveguide 116 is connected to the input terminal 115 in the electro-optical modulator, so as to detect the modulated optical signal.

This application provides a method for manufacturing an electro-optical modulator, providing a substrate, a dielectric layer is formed on the substrate, an input waveguide and an output waveguide are formed in the dielectric layer, and an electro-optical crystal film layer is bonded on the dielectric layer. The film layer includes a ridge structure. The electro-optical modulation efficiency of the ridge structure is higher than that of the input waveguide and the output waveguide. The ridge structure may include an input coupling part and an output coupling part. The input coupling part is used to align the input waveguide with the input waveguide. The signal in the standard is coupled to the ridge structure, and the output coupling part and the part are used to couple the signal in the ridge structure to the output waveguide alignment, and metal electrodes are formed on both sides of the ridge structure on the surface of the electro-optic crystal film layer. In this way, the light in the first input waveguide can be coupled to the ridge structure through the input coupling part. When there is a modulation signal in the metal electrode, the refractive index in the ridge structure can be changed to modulate the signal therein. The light coupled to the output waveguide in the output coupling part of the shape structure is modulated, and the electro-optic crystal has a higher modulation efficiency, so the efficiency of the electro-optic modulation is improved. At the same time, the embodiment of the present application combines the electro-optic crystal film layer and other The advantage of the waveguide is that there is no need to etch the electro-optic crystal film to realize a passive waveguide, thus avoiding the complicated process problems caused by a large number of etching of the electro-optic crystal film and simplifying the manufacturing process. In addition, the transparent conductive layer is also used to reduce the absorption of the optical signal during the modulation process, shorten the distance between the electrodes applying the modulation signal, improve the modulation efficiency, and help reduce the size of the electro-optic modulator. The crystal electro-optic modulator and other devices are integrated on the same substrate, realizing a small-sized and low-cost integrated ICTR optical chip.

Based on the method for manufacturing an electro-optic modulator provided by the above embodiments, an embodiment of the present application also provides an electro-optic modulator. Referring to FIG. 9, it is a schematic structural diagram of an electro-optic modulator provided by an embodiment of the present application. include:

Substrate 10;

The dielectric layer 100 may be disposed on the substrate 10, and the dielectric layer 100 may include an input waveguide 112 and an output waveguide 113;

The electro-optic crystal film layer 120 is disposed on the dielectric layer 100 and is bonded to the surface of the dielectric layer 100. The electro-optic crystal film layer 120 includes a ridge structure 121. The ridge structure 121 includes an input coupling part and an output coupling part. Part is used to couple the signal in the input waveguide 112 to the ridge structure for alignment, and the output coupling part is used to couple the signal in the ridge structure to and output the waveguide 113;

The metal electrodes are arranged on the surface of the electro-optic crystal film layer and located on both sides of the ridge structure 121.

The dielectric layer 100 may provide a confinement effect for the light in the optical waveguide therein, and specifically, may be silicon oxide, silicon nitride, or the like.

That is to say, in addition to the input waveguide 112 and the output waveguide 113, the dielectric layer 100 may also include other waveguides, the other waveguides may include the first optical splitter 111 and the second optical splitter 114, and the other waveguides may also include connecting waveguides and deflection waveguides. Passive waveguides such as conversion waveguide, input end 110, output end 115, etc. Other waveguides may be formed on the same layer as the input waveguide 112 and the output waveguide 113, and the material of these waveguides may be the same as the material of the input waveguide 112 and the output waveguide 113.

In the embodiment of the present application, the input waveguide 112 and the output waveguide 113 may be covered by the dielectric layer 100.

The electro-optic crystal film layer 120 can be formed on the surface of the dielectric layer 100 by bonding. The electro-optic crystal film layer can be a film layer of materials such as lithium niobate, indium phosphide, or tantalum niobate. Take lithium niobate as an example. The material is relatively hard, and the passive waveguide obtained by etching the wafer-level lithium niobate alone will cause the process to be too complicated. However, the bonding method can combine the silicon waveguide with the lithium niobate waveguide, or the nitride The combination of the silicon waveguide and the lithium niobate waveguide avoids the process difficulty of a large amount of etching on the lithium niobate film to form a passive waveguide. At the same time, no adhesive is used in the bonding process, which improves the stability of the connection.

The electro-optic crystal film layer 120 may include doping elements, and the doping elements may be helium ions, hydrogen ions, nitrogen ions, etc., for details, please refer to the description of S102.

The electro-optic crystal film 120 may include a ridge structure 121 for enhancing light confinement when guiding light. The ridge structure 121 may include an input coupling part and an output coupling part, wherein the input coupling part can be aligned with the input waveguide 112 in the longitudinal direction, so that the signal in the input waveguide 112 can be coupled to the ridge structure through the input coupling part, and the output coupling The part can be aligned with the output waveguide 113 in the longitudinal direction, so that the signal in the ridge structure can be coupled to the output waveguide 113 through the output coupling part. That is, the signal in the input waveguide 112 can be coupled to the input coupling part in the ridge structure 121 to be transmitted in the ridge structure 121, and then the signal is coupled to the output waveguide 113 through the output coupling part for continued transmission (refer to 6(b) and 6(c) in the direction of the dashed arrow), for example, to other devices integrated with the photoelectric modulator on the same substrate.

Since the ridge structure 121 is used to connect the input waveguide 112 and the output waveguide 113, its extension direction may be the connection direction between the output end of the input waveguide 112 and the input end of the output waveguide 113. Based on different electro-optic modulators, there can be different numbers of ridge structures 121. In the scenario where the optical signal in a single waveguide is phase modulated, an electro-optic modulator can include an input waveguide 112 and an output waveguide 113. In this case, A ridge structure 121 can be provided; in a scenario where two arms form an interference structure to modulate the intensity of an optical signal, an electro-optic modulator can include two input waveguides 113 and two output waveguides 113, in which case two The ridge structures 121 are arranged in parallel, the input coupling part of each ridge structure 121 is aligned with one input waveguide 112, and the output coupling part is aligned with one output waveguide 113.

In the embodiment of the present application, it may also include metal electrodes 130 formed on the surface of the electro-optic crystal film 120 on both sides of the ridge structure 121. For the electro-optic crystal material, based on the Pockels effect, the electric field applied to the optical field region The larger the value, the stronger the electro-optic effect, and the stronger the corresponding phase modulation. Therefore, the metal electrodes 130 on both sides of the ridge structure 121 can provide a certain electric field for the ridge structure 121, so that the refractive index in the ridge structure 121 increases with the voltage The phase modulation of the optical signal in the ridge structure 121 is realized.

Specifically, in the scene where the interference structure is formed by two arms to modulate the intensity of the optical signal, two parallel ridge structures 121 can be provided, so that three metal electrodes 130 can be provided, and the ridge structures 121 can be provided. For the common signal electrode, two ground electrodes are respectively arranged on the outside of the ridge structure 121, which can also achieve the voltage difference between the two sides of the ridge structure 121. Refer to FIG. 7, where FIG. 7(a) is a top view of the electro-optic modulator, and FIG. 7(b) is a cross-sectional view of the electro-optic modulator in FIG. 7(a) along the AA direction. At this time, the two ridge structures 121 are applied with opposite voltages, so their phases are modulated in opposite directions. The final phase difference is double the phase modulated by a single modulator, which improves the modulation efficiency. Optical signals with phase difference can interfere after being merged, and their intensity is determined by the magnitude of the phase difference, so the phase modulation can be converted into modulation.

In the embodiment of the present application, the electro-optic modulator may further include a transparent conductive layer 140 disposed between the metal electrode 130 and the ridge structure 121. Specifically, the electro-optic crystal film layer 120 and the metal layer may be disposed on both sides of the ridge structure 121. A transparent electrode layer 140 is formed between the electrodes 130, wherein the distance between the transparent conductive layer 140 and the ridge structure 121 is smaller than the distance between the metal electrode 130 and the ridge structure 121, because the transparent conductive layer 140 absorbs light signals weakly , It causes less optical loss, and can increase the electric field in the ridge structure 121 to a certain extent, reduce the half-wave voltage, and improve the modulation efficiency. Therefore, it balances the optical loss of the modulation efficiency and realizes the overall optimization of electro-optical modulation. .

The transparent conductive layer 140 may be a transparent conductive oxide layer, for example, indium tin oxide or the like.

Since the transparent conductive layer 140 absorbs less light signals, the transparent conductive layer 140 can be in contact with the ridge structure 121, or even with the ridge structure 121, that is, the transparent conductive layer 140 on both sides of the ridge structure 121 The distance between the ridge structure 121 can be greater than or equal to the dimension in the direction perpendicular to the extension direction of the ridge structure 121, that is, the distance between the transparent conductive layers can be d ₃ , (d3 is greater than or equal to d2 and less than d1). _{The distance d 1} between the electrodes 130 is smaller than the distance d ₃ , so a smaller distance between the electrodes can be obtained, thereby increasing the electric field in the ridge structure 121 and improving the modulation efficiency. As an example, after the transparent conductive layer 140 is added, the distance between the electrodes is reduced from 3.5um to 0.9um, so that the electro-optical modulation efficiency achieved by the ridge structure 121 of the same size is increased by 7.5 times, which is beneficial to improve the electro-optical Modulation efficiency and reducing the size of electro-optic modulators.

Thereafter, in order to improve the reliability between the metal electrode 130 and the ridge structure 121, an insulating layer between the metal electrode 130 and the ridge structure 121 may also be included in the embodiment of the present application. The insulating layer may be a light-transmitting material or It can be an opaque material.

Based on the electro-optical modulator provided by the above embodiments, the embodiment of the present application also provides an integrated chip. The integrated chip may include the electro-optical modulator and other devices. The electro-optical modulator and other devices may be formed on the same substrate, and other devices may be formed on the same substrate. And the electro-optic modulator is connected through a connecting waveguide. Other devices can be at least one of laser diodes, semiconductor optical amplifiers, and photodetectors. It is understandable that there can be multiple devices of one type on the same substrate, and each device can be connected in any desired connection sequence. .

Referring to FIG. 10, a schematic diagram of the device structure of an integrated chip provided by this embodiment of the application. A laser diode, an electro-optic modulator, and an SOA can be sequentially formed on a substrate. In this way, the laser diode can generate an optical carrier, and the electro-optic modulator can The optical carrier is modulated to form an optical signal, and the SOA can discharge the optical signal; or a laser diode, SOA, and an electro-optic modulator can be formed on the substrate in sequence, so that the SOA can amplify the optical carrier generated by the laser diode, and the electro-optic The modulator can modulate the amplified optical carrier to obtain an optical signal; or a micro photodetector, a laser diode, an SOA, and an electro-optical debugger can be formed on the substrate in sequence, so that the micro photodetector can perform the optical carrier generated by the laser diode. For detection, SOA can amplify the optical carrier generated by the laser diode, and the electro-optical modulator can modulate the amplified optical carrier to obtain an optical signal. It should be noted that the above is only an example of an integrated chip, and those skilled in the art can form other combinations of the above-mentioned electro-optical modulator and other devices according to actual conditions, which will not be illustrated here.

Indium phosphide can be used as a base material in other devices such as laser diodes, semiconductor optical amplifiers, and photodetectors to obtain efficient device structures.

The embodiment of this application proposes a hybrid integrated ICTR chip, which includes SOI/SiNx passive waveguides with excellent performance, InP material laser diodes, semiconductor optical amplifiers, photodetectors and other active structures, and high electro-optic crystal materials. Bandwidth, low driving voltage, temperature-insensitive modulator, use evanescent wave coupling in each layer of material to achieve optical transmission, under the premise of improving the performance of the device, improve the integration of the chip, and is conducive to packaging, greatly reducing Chip size and cost.

The above is the specific implementation of this application. It should be understood that the above embodiments are only used to illustrate the technical solutions of the present application, not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, a person of ordinary skill in the art should understand that: The technical solutions recorded in the embodiments are modified, or some of the technical features are equivalently replaced; these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

A manufacturing method of an electro-optical modulator, characterized in that it comprises:

Providing a substrate; a dielectric layer is formed on the substrate, and an input waveguide and an output waveguide are formed in the dielectric layer;

Bonding an electro-optical crystal film layer on the surface of the dielectric layer; the electro-optical crystal film layer includes a ridge structure; the electro-optical modulation efficiency of the ridge structure is higher than that of the input waveguide and the output waveguide; The ridge structure includes an input coupling part and an output coupling part; the input coupling part is used to couple the signal in the input waveguide to the ridge structure, and the output coupling part is used to couple the ridge structure The signal in is coupled to the output waveguide;

Metal electrodes are formed on the surface of the electro-optic crystal film on both sides of the ridge structure.
The method according to claim 1, wherein the bonding an electro-optic crystal film layer on the surface of the dielectric layer comprises:

Bonding an electro-optic crystal structure on the surface of the dielectric layer; the electro-optic crystal structure includes an electro-optic crystal base structure and an electro-optic crystal film layer including doping elements, the electro-optic crystal film layer faces the dielectric layer;

Heating to remove the electro-optic crystal substrate structure;

The electro-optic crystal film layer is etched to form a ridge structure.
The method according to claim 1 or 2, wherein the material of the electro-optic crystal film layer is lithium niobate, indium phosphide or tantalum niobate.
The method according to any one of claims 1 to 3, wherein the forming metal electrodes on both sides of the ridge structure on the surface of the electro-optic crystal film layer comprises:

Forming a transparent conductive layer on both sides of the ridge structure on the surface of the electro-optic crystal film layer;

A metal electrode is formed on the transparent conductive layer, and the lateral distance between the transparent conductive layer and the ridge structure is smaller than the lateral distance between the metal electrode and the ridge structure.
The method according to any one of claims 1 to 4, wherein the input waveguide and the output waveguide are silicon or silicon nitride.
The method according to any one of claims 1-5, wherein the dielectric layer further comprises a first optical splitter connected to the input ends of the two input waveguides, and a first optical splitter connected to the two output waveguides. The second optical splitter connected to the output end of the electro-optic crystal film layer has two ridge structures, and each of the ridge structures is respectively coupled with an input waveguide and an output waveguide to realize signal coupling.
7. The method according to claim 6, wherein the metal electrodes shared between the two ridge structures are signal electrodes, and the two metal electrodes respectively disposed outside the two ridge structures are ground electrodes.
The method according to any one of claims 1-7, further comprising:

An insulating layer is formed between the ridge structure and the metal electrode.
The method according to any one of claims 1-8, further comprising:

Other devices are formed on the substrate in areas other than the electro-optical modulator; the other devices are at least one of a laser diode, a semiconductor optical amplifier, and a photodetector; the laser diode is used to generate an optical carrier The electro-optical modulator is used to modulate the electrical signal on the metal electrode to the optical carrier to form an optical signal; the semiconductor optical amplifier is used to amplify the optical carrier and/or the optical signal; the photodetector is used to Optical carrier and/or optical signal for detection.
An electro-optical modulator, characterized in that it comprises:

Substrate

A dielectric layer disposed on the substrate, and the dielectric layer includes an input waveguide and an output waveguide;

The electro-optic crystal film layer is disposed on the dielectric layer and bonded to the surface of the dielectric layer, the electro-optic crystal film layer includes a ridge structure, and the electro-optical modulation efficiency of the ridge structure is higher than that of the input waveguide And the electro-optical modulation efficiency of the output waveguide; the ridge structure includes an input coupling part and an output coupling part; the input coupling part is used to couple the signal in the input waveguide to the ridge structure, and the output The coupling part is used to couple the signal in the ridge structure to the output waveguide;

Metal electrodes are arranged on the surface of the electro-optic crystal film layer and located on both sides of the ridge structure.
11. The electro-optic modulator of claim 10, wherein the electro-optic crystal film layer includes a doping element.
The electro-optic modulator according to any one of claims 10-11, wherein the material of the electro-optic crystal film layer is lithium niobate, indium phosphide or tantalum niobate.
The electro-optical modulator according to any one of claims 10-12, further comprising:

The transparent conductive layer is arranged between the electro-optic crystal film layer on both sides of the ridge structure and the metal electrode; the lateral distance between the transparent conductive layer and the ridge structure is smaller than the metal electrode and the ridge structure The horizontal distance between structures.
The electro-optical modulator according to any one of claims 10-13, wherein the input waveguide and the output waveguide are silicon or silicon nitride.
The electro-optical modulator according to any one of claims 10-14, further comprising:

The first optical splitter is arranged in the dielectric layer and connected to the input ends of the two input waveguides;

The second optical splitter is arranged in the dielectric layer and connected to the output ends of the two output waveguides;

Then there are two ridge structures on the electro-optic crystal film layer, and each of the ridge structures is respectively coupled with an input waveguide and an output waveguide to realize signal coupling.
The electro-optical modulator according to claim 15, wherein the metal electrode comprises a signal electrode and two ground electrodes, the signal electrode is arranged between the two ridge structures, and the two ground electrodes The electrodes are respectively arranged outside the two ridge structures.
The electro-optical modulator according to any one of claims 10-16, further comprising:

The insulating layer is arranged between the ridge structure and the metal electrode.
A chip, characterized in that the chip includes at least one of a laser diode, a semiconductor optical amplifier, and a photodetector, and the electro-optical modulator according to any one of claims 10-17;

The laser diode is used to generate an optical carrier;

The electro-optical modulator is used to modulate the electric signal on the metal electrode into an optical carrier to form an optical signal;

The semiconductor optical amplifier is used to amplify an optical carrier or an optical signal;

The photodetector is used for detecting optical carrier or optical signal.