Silicon-integrated magneto-optical sensor chip and its manufacturing method

Abstract

This application relates to a silicon photonics integrated magneto-optical sensor chip and its manufacturing method. A strip waveguide is formed within a functional layer, and two spaced-apart piezoelectric thin films are formed on the strip waveguide, with the extension direction of the strip waveguide and the extension direction of the piezoelectric thin films being the same. An optical core layer is formed within the strip waveguide, with the orthographic projection of the optical core layer onto the plane of the piezoelectric thin films located between the two piezoelectric thin films, and the distance between the optical core layer and the two piezoelectric thin films being the same. This causes the piezoelectric thin films to deform when energized, generating a symmetrical panda-shaped stress field on both sides of the strip waveguide. This forms a polarization-maintaining waveguide structure including the strip waveguide, the piezoelectric thin films, and the optical core layer, effectively improving the polarization stability and integration density of the silicon photonics integrated magneto-optical sensor chip.

Description

Technical Field

[0001] This application relates to the field of magnetic field sensor technology, and in particular to a silicon photonic integrated magneto-optical sensor chip and its manufacturing method. Background Technology

[0002] Magnetic field sensors have wide applications in various fields such as industrial detection, environmental monitoring, biomedicine, and scientific research. With the development of micro-nano fabrication and integrated photonics technology, on-chip integrated magnetic field sensors have gradually become a research and application hotspot due to their advantages such as small size, low power consumption, and ease of system integration.

[0003] Generally, magnetic field sensors often employ a combination of discrete magneto-optical materials (such as TGG crystals) and polarization-maintaining fibers to achieve high sensitivity. However, this combination suffers from problems such as large size, difficulty in integration, and poor process compatibility, limiting the application of magnetic field sensors in miniaturized platforms. In recent years, the high integration, low transmission loss, and good CMOS process compatibility of silicon-based photonics platforms (such as SOI) have provided strong support for the on-chip integration of optical devices. However, when achieving high-performance magneto-optical sensing functions, especially in maintaining the stability of optical polarization in complex integrated environments, magnetic field sensors still face the challenge of simultaneously achieving high magneto-optical coefficients, low transmission loss, and stable polarization maintenance capabilities. Summary of the Invention

[0004] Therefore, it is necessary to provide a silicon photonic integrated magneto-optical sensor chip and its manufacturing method to improve the polarization stability and integration of the silicon photonic integrated magneto-optical sensor chip.

[0005] This application provides a method for manufacturing a silicon photonic integrated magneto-optical sensing chip, comprising:

[0006] A silicon wafer is provided, and a buffer layer is formed on the substrate of the silicon wafer;

[0007] A functional layer is formed on the buffer layer;

[0008] The functional layer is etched to form a strip waveguide and a grating coupler within the functional layer, with the grating coupler located on both sides of the strip waveguide;

[0009] Two piezoelectric thin films spaced apart are formed on the strip waveguide, and the extension direction of the strip waveguide is the same as the extension direction of the piezoelectric thin films.

[0010] An optical core layer is formed within the strip waveguide. The orthographic projection of the optical core layer onto the plane containing the piezoelectric thin films is located between the two piezoelectric thin films, and the optical core layer is equidistant from the two piezoelectric thin films, thereby forming a polarization-maintaining waveguide structure comprising the strip waveguide, the piezoelectric thin films, and the optical core layer.

[0011] In one embodiment, after forming the optical core layer, the method further includes:

[0012] A first insulating encapsulation layer is formed on the functional layer, the piezoelectric film, and the optical core layer;

[0013] A quantum dot laser and a photodetector are formed on the first insulating encapsulation layer, and the orthographic projection of the quantum dot laser toward the substrate at least partially coincides with the orthographic projection of one of the grating couplers toward the substrate, and the orthographic projection of the photodetector toward the substrate at least partially coincides with the orthographic projection of another of the grating couplers toward the substrate.

[0014] A second insulating encapsulation layer is formed on the first insulating encapsulation layer to cover the quantum dot laser and the photodetector;

[0015] A first electrical connection is formed within the first insulating encapsulation layer and the second insulating encapsulation layer.

[0016] In one embodiment, after forming the first electrical connection, the method further includes:

[0017] A wafer is provided, the wafer including a substrate and a semiconductor structure formed on the substrate;

[0018] A second electrical connection is formed within the substrate;

[0019] The wafer is bonded to the silicon wafer, such that the substrate is bonded to the side of the second insulating encapsulation layer away from the substrate, and the first electrical connector and the second electrical connector are connected.

[0020] Accordingly, this application also provides a silicon photonics integrated magneto-optical sensing chip, comprising:

[0021] Silicon wafer, the silicon wafer including a substrate;

[0022] A buffer layer is located on the substrate;

[0023] A functional layer is located on the buffer layer. The functional layer includes a strip waveguide and a grating coupler, with the grating coupler located on both sides of the strip waveguide.

[0024] The polarization-maintaining waveguide structure includes the strip waveguide, two spaced-apart piezoelectric thin films, and an optical core layer; wherein,

[0025] The piezoelectric thin film is located on the strip waveguide, and the extension direction of the piezoelectric thin film is the same as the extension direction of the strip waveguide;

[0026] The optical core layer is located inside the strip waveguide. The orthographic projection of the optical core layer onto the plane containing the piezoelectric thin film is located between the two piezoelectric thin films, and the optical core layer is at the same distance from the two piezoelectric thin films.

[0027] In one embodiment, both the piezoelectric thin film and the optical core layer are strip-shaped structures, and the piezoelectric thin film, the optical core layer and the strip waveguide all extend in the same direction.

[0028] In one embodiment, the grating coupler is located on both sides of the strip waveguide along an extension direction perpendicular to the strip waveguide;

[0029] The grating coupler includes a plurality of grating grooves that are parallel to each other and spaced apart within the functional layer, and the extending direction of the grating grooves is perpendicular to the extending direction of the strip waveguide.

[0030] In one embodiment, when the piezoelectric film is energized, the strip waveguide beneath the piezoelectric film includes a dual stress field symmetrically distributed around the optical core layer.

[0031] In one embodiment, the substrate includes a silicon-on-insulator substrate, the functional layer is made of terbium-doped silicon nitride, the piezoelectric thin film is made of aluminum nitride, and the implanted ions in the core layer include thallium ions.

[0032] In one embodiment, the silicon photonic integrated magneto-optical sensing chip further includes:

[0033] A first insulating encapsulation layer is located on the functional layer, the piezoelectric film, and the optical core layer;

[0034] A quantum dot laser is located on the first insulating encapsulation layer, wherein the orthographic projection of the quantum dot laser toward the substrate at least partially coincides with the orthographic projection of the grating coupler toward the substrate;

[0035] A photodetector is located on the first insulating encapsulation layer, and the orthographic projection of the photodetector toward the substrate at least partially coincides with the orthographic projection of the other grating coupler toward the substrate;

[0036] A second insulating encapsulation layer is located on the first insulating encapsulation layer and covers the quantum dot laser and the photodetector;

[0037] A first electrical connector, located within the first and second insulating encapsulation layers, is used to bring out the piezoelectric thin film, the quantum dot laser, and the photodetector.

[0038] In one embodiment, the silicon photonic integrated magneto-optical sensing chip further includes:

[0039] A wafer, including a substrate and a semiconductor structure formed on the substrate;

[0040] A second electrical connector, located within the substrate, is used to bring out the semiconductor structure;

[0041] The wafer and the silicon wafer are bonded together, the substrate is located on the second insulating encapsulation layer, and the first electrical connector and the second electrical connector are connected.

[0042] In summary, this application provides a silicon photonics integrated magneto-optical sensing chip and its manufacturing method. By forming a strip waveguide within a functional layer, and then forming two spaced-apart piezoelectric thin films on the strip waveguide, with the extension directions of the strip waveguide and the piezoelectric thin films being the same, and forming an optical core layer within the strip waveguide, the orthographic projection of the optical core layer onto the plane of the piezoelectric thin films lies between the two piezoelectric thin films, and the distance between the optical core layer and the two piezoelectric thin films is the same. This causes the piezoelectric thin films to deform when energized, generating a symmetrical panda-shaped stress field on both sides of the strip waveguide. The magneto-optically active optical core layer is precisely positioned at the center of symmetry of the stress field formed by the strip waveguide, thereby forming a polarization-maintaining waveguide structure including the strip waveguide, the piezoelectric thin films, and the optical core layer. This achieves stable control of the polarization state of the light wave by the stress field and synergistic enhancement of the magneto-optical effect, effectively improving the polarization stability and integration of the silicon photonics integrated magneto-optical sensing chip. Attached Figure Description

[0043] To more clearly illustrate the technical solutions in the embodiments of this application or the conventional technology, the drawings used in the description of the embodiments or the conventional technology will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0044] Figure 1 A flowchart illustrating a method for manufacturing a silicon photonic integrated magneto-optical sensor chip according to one embodiment of this application.

[0045] Figure 2 This is a schematic diagram of the structure corresponding to the step of providing a silicon wafer in the manufacturing method of a silicon photonic integrated magneto-optical sensor chip provided in one embodiment of this application.

[0046] Figure 3 This is a schematic diagram of the structure corresponding to the step of forming a buffer layer on a silicon wafer substrate in the manufacturing method of a silicon photonic integrated magneto-optical sensor chip provided in one embodiment of this application.

[0047] Figure 4This is a schematic diagram of the structure corresponding to the step of forming a functional layer on a buffer layer in the manufacturing method of a silicon photonic integrated magneto-optical sensor chip provided in one embodiment of this application.

[0048] Figure 5 This is a schematic diagram of the structure corresponding to the step of etching the functional layer in the manufacturing method of the silicon photonic integrated magneto-optical sensor chip provided in one embodiment of this application.

[0049] Figure 6 This is a top view of the structure corresponding to the step of etching the functional layer in the manufacturing method of the silicon photonic integrated magneto-optical sensor chip provided in one embodiment of this application.

[0050] Figure 7 This is a schematic diagram of the structure corresponding to the step of forming a piezoelectric thin film on a strip waveguide in the manufacturing method of a silicon photonic integrated magneto-optical sensing chip provided in one embodiment of this application.

[0051] Figure 8 This is a schematic diagram of the structure corresponding to the step of forming an optical core layer in a strip waveguide in the manufacturing method of a silicon photonic integrated magneto-optical sensing chip provided in one embodiment of this application.

[0052] Figure 9 This is a schematic diagram of the structure corresponding to the step of forming a first insulating encapsulation layer on the functional layer, the piezoelectric thin film, and the optical core layer in the manufacturing method of the silicon photonic integrated magneto-optical sensing chip provided in one embodiment of this application.

[0053] Figure 10 This is a schematic diagram of the structure corresponding to the step of forming a quantum dot laser and a photodetector on a first insulating encapsulation layer in the manufacturing method of a silicon photonic integrated magneto-optical sensing chip provided in one embodiment of this application.

[0054] Figure 11 This is a schematic diagram of the structure corresponding to the step of forming a second insulating encapsulation layer and a first electrical connector on a first insulating encapsulation layer in the manufacturing method of a silicon photonic integrated magneto-optical sensing chip provided in one embodiment of this application.

[0055] Figure 12 This is a schematic diagram illustrating the propagation of a laser beam in the functional layer during the manufacturing method of a silicon photonic integrated magneto-optical sensing chip provided in one embodiment of this application.

[0056] Figure 13 This is a schematic cross-sectional view of the strip waveguide in a silicon photonic integrated magneto-optical sensing chip provided in one embodiment of this application.

[0057] The reference numerals in the figures include: 100-substrate; 101-first substrate material layer; 102-insulating layer; 103-second substrate material layer; 110-buffer layer; 120-functional layer; 121-strip waveguide; 121a-inductive waveguide unit; 121b-reference waveguide unit; 122-grating coupler; 122a-first grating coupler; 122b-second grating coupler; 122c-third grating coupler; 123-beam splitter; 124-multimode interferometer; 130-piezoelectric thin film; 140-optical core layer; 150-first insulating encapsulation layer; 160-quantum dot laser; 170-photodetector; 180-second insulating encapsulation layer; 181-first electrical connector; 200-substrate; 201-second electrical connector; 210-semiconductor structure; W1-silicon wafer; W2-wafer; t-grating groove. Detailed Implementation

[0058] To facilitate understanding of this application, a more complete description will be provided below with reference to the accompanying drawings, which illustrate embodiments of the present application. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that the disclosure of this application will be more thorough and complete.

[0059] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0060] It should be understood that when an element or layer is referred to as "on," "adjacent to," "connected to," or "coupled to" other elements or layers, it may be directly on, adjacent to, connected to, or coupled to other elements or layers, or there may be intervening elements or layers. Conversely, when an element is referred to as "directly on," "directly adjacent to," "directly connected to," or "directly coupled to" other elements or layers, there are no intervening elements or layers. It should be understood that although the terms first, second, third, etc., may be used to describe various elements, parts, regions, layers, doping types, and / or portions, these elements, parts, regions, layers, doping types, and / or portions should not be limited by these terms. These terms are only used to distinguish one element, part, region, layer, doping type, or portion from another element, part, region, layer, doping type, or portion. Therefore, without departing from the teachings of this application, the first element, component, region, layer, doping type, or portion discussed below may be represented as a second element, component, region, layer, or portion; for example, the first doping type may be referred to as the second doping type, and similarly, the second doping type may be referred to as the first doping type; the first doping type and the second doping type are different doping types, for example, the first doping type may be P-type and the second doping type may be N-type, or the first doping type may be N-type and the second doping type may be P-type.

[0061] Spatial relation terms such as “below,” “under,” “below,” “under,” “above,” “above,” etc., are used herein to describe the relationship between one element or feature shown in the figure and other elements or features. It should be understood that, in addition to the orientation shown in the figure, spatial relation terms also include different orientations of the device in use and operation. For example, if the device in the figure is flipped, the element or feature described as “below,” “under,” or “below” will be oriented “above” the other element or feature. Therefore, the exemplary terms “below” and “under” can include both above and below orientations. Furthermore, the device may also include other orientations (e.g., rotated 90 degrees or other orientations), and the spatial descriptive terms used herein will be interpreted accordingly.

[0062] When used herein, the singular forms of “a,” “an,” and “ / the” may also include the plural forms unless the context clearly indicates otherwise. It should also be understood that the terms “comprising / including” or “having,” etc., specify the presence of the stated features, wholes, steps, operations, components, parts, or combinations thereof, but do not preclude the possibility of the presence or addition of one or more other features, wholes, steps, operations, components, parts, or combinations thereof. Meanwhile, in this specification, the term “and / or” includes any and all combinations of the associated listed items.

[0063] Magnetic field measurement techniques based on the Faraday effect offer advantages such as non-contact operation and high sensitivity. However, traditional magnetic field sensors rely on a combination of discrete magneto-optical crystals (e.g., TGG) and polarization-maintaining fibers, resulting in large size, low integration density, and poor process compatibility. The rapid development of silicon-based integrated photonics has provided an ideal platform for miniaturized devices; for example, the silicon-on-insulator (SOI) platform offers low loss, high integration density, and good CMOS compatibility. However, on-chip integration of magneto-optical functional devices still faces challenges related to material heterogeneity and insufficient polarization stability.

[0064] Therefore, it is necessary to provide a silicon photonic integrated magneto-optical sensor chip and its manufacturing method to improve the polarization stability and integration of the silicon photonic integrated magneto-optical sensor chip.

[0065] Figure 1 This is a flowchart illustrating a method for manufacturing a silicon-photon integrated magneto-optical sensing chip according to one embodiment of this application. (See also...) Figure 1 One embodiment of this application provides a method for manufacturing a silicon photonic integrated magneto-optical sensor chip, which includes the following steps S01 to S05.

[0066] Step S01: Provide a silicon wafer and form a buffer layer on the substrate of the silicon wafer.

[0067] It should be noted that the buffer layer can effectively alleviate the stress caused by the difference in thermal expansion coefficients between the substrate and other subsequently formed film layers, and can also adjust the refractive index difference between the substrate and the subsequently formed functional layers, thereby optimizing the light transmission characteristics in the waveguide.

[0068] Step S02: Form a functional layer on the buffer layer.

[0069] Step S03: Etch the functional layer to form a strip waveguide and a grating coupler within the functional layer, with the grating coupler located on both sides of the strip waveguide.

[0070] Step S04: Two piezoelectric thin films spaced apart are formed on the strip waveguide, and the extension direction of the strip waveguide is the same as the extension direction of the piezoelectric thin films.

[0071] It should be noted that the piezoelectric film deforms when energized, generating a symmetrical panda-shaped stress field on both sides of the strip waveguide, giving the strip waveguide a fast axis and a slow axis, and giving the strip waveguide polarization-maintaining properties.

[0072] Step S05: An optical core layer is formed in the strip waveguide. The orthographic projection of the optical core layer onto the plane of the piezoelectric thin film is located between the two piezoelectric thin films, and the optical core layer is equidistant from the two piezoelectric thin films, thereby forming a polarization-maintaining waveguide structure including the strip waveguide, the piezoelectric thin films, and the optical core layer.

[0073] The manufacturing method of the silicon photonic integrated magneto-optical sensor chip described above involves forming a strip waveguide within a functional layer, forming two spaced-apart piezoelectric thin films on the strip waveguide, and forming an optical core layer within the strip waveguide. This causes the piezoelectric thin films to deform when energized, generating a symmetrical panda-shaped stress field on both sides of the strip waveguide. The magneto-optically active optical core layer is precisely positioned at the center of symmetry of the stress field formed by the strip waveguide, thereby forming a polarization-maintaining waveguide structure including the strip waveguide, the piezoelectric thin films, and the optical core layer. This achieves stable control of the polarization state of the light wave by the stress field and synergistic enhancement of the magneto-optical effect, effectively improving the polarization stability and integration of the silicon photonic integrated magneto-optical sensor chip.

[0074] Figures 2 to 10 This is a schematic diagram showing some steps in the manufacturing method of a silicon photonic integrated magneto-optical sensor chip provided in one embodiment of this application. The following is a combined view with... Figures 2 to 12 This application describes in detail a method for manufacturing a silicon photonic integrated magneto-optical sensing chip according to one embodiment.

[0075] First, refer to Figure 2 and Figure 3 A silicon wafer W1 is provided, and a buffer layer 110 is formed on a substrate 100 of the silicon wafer W1. In one embodiment, the substrate 100 is a silicon on insulator (SOI) substrate, and the substrate 100 includes a first substrate material layer 101, an insulating layer 102 and a second substrate material layer 103 stacked sequentially from bottom to top, wherein the materials of the first substrate material layer 101 and the second substrate material layer 103 both include silicon material, and the material of the insulating layer 102 includes silicon oxide.

[0076] Continue reading Figure 3In one embodiment, a buffer layer 110 is formed on a substrate 100 using a deposition process. Optionally, the buffer layer 110 is formed using plasma-enhanced chemical vapor deposition (PECVD). Specifically, the process of forming the buffer layer 110 using PECVD includes: placing two electrodes (not shown in the figure) above and below the substrate 100, respectively, and connecting the two electrodes to a dual-frequency radio frequency power supply; introducing silane (SiH4) and nitrous oxide (N2O) into a reaction chamber, with the gas flow rate ratio of silane to nitrous oxide being approximately 1:10, to deposit the buffer layer 110 on the substrate 100. Optionally, the material of the buffer layer 110 includes silicon dioxide (SiO2), and the deposition thickness of the buffer layer 110 ranges from 0.5 μm to 1 μm.

[0077] It should be noted that using a dual-frequency RF power supply can effectively reduce the ignition voltage, which is more conducive to obtaining a stable plasma source. Forming a buffer layer on the substrate can effectively alleviate the stress caused by the difference in thermal expansion coefficients between the substrate and other subsequently deposited films, and can also adjust the refractive index difference between the substrate and the functional layer, thereby optimizing the light transmission characteristics in the waveguide.

[0078] Next, refer to Figure 4 A functional layer 120 is formed on the buffer layer 110. In one embodiment, the functional layer 120 is formed using a plasma-enhanced chemical vapor deposition (PECVD) process. Specifically, the process of forming the functional layer 120 using PECVD includes: placing two electrodes (not shown) above and below the substrate 100, respectively, and connecting the two electrodes to a dual-frequency radio frequency power supply; introducing silane (SiH4) and ammonia (NH3) into the reaction chamber, wherein the silane is used to provide a silicon source, and the ammonia is used to provide nitrogen and react with the silicon source gas to generate silicon nitride. Optionally, the thickness of the functional layer 120 ranges from 0.5 μm to 0.8 μm.

[0079] In other embodiments of this application, a silicon nitride layer can be deposited as a functional layer using co-sputtering. During the formation of the silicon nitride layer, silicon nitride (Si3N4) is used as the target material, and a mixture of argon (Ar) and nitrogen (N2) is used as the sputtering gas (the ratio of argon to nitrogen is 4:1). The temperature of the substrate is, for example, 300°C.

[0080] In one embodiment, after forming the buffer layer and before forming the functional layer on the buffer layer, the method for manufacturing the silicon photonic integrated magneto-optical sensor chip further includes: planarizing the buffer layer to improve its surface flatness. Optionally, a chemical mechanical polishing (CMP) process is used for planarization.

[0081] Then refer to Figure 5 and Figure 6 ( Figure 6 for Figure 5 The diagram shows a top view of the functional layer 120. The functional layer 120 is etched to form a strip waveguide 121 and a grating coupler 122 within it, with the grating coupler 122 located on both sides of the strip waveguide 121. Exemplarily, the etching process of the functional layer 120 includes: uniformly coating photoresist on the functional layer 120, and performing photolithography and development on the photoresist to form a patterned photoresist layer (not shown in the figure); based on the patterned photoresist layer, etching the portion of the functional layer not covered by the photoresist layer using a wet etching process to form the strip waveguide 121 and the grating coupler 122. The strip waveguide 121 has a rectangular cross-sectional shape along a direction parallel to the surface of the functional layer 120. Optionally, the cross-sectional width of the strip waveguide 121 is, for example, 500 nm, and the cross-sectional thickness is, for example, 220 nm.

[0082] Continue reading Figure 5 In one embodiment, grating couplers 122 are located on both sides of the strip waveguide 121 along its extension direction (or length direction), and the grating couplers 122 include a plurality of parallel and spaced-apart grating grooves t, the extension direction of which is perpendicular to the extension direction of the strip waveguide 121. Optionally, the depth of the grating grooves t in the grating coupler 122 is, for example, 140 nm, the grating period is, for example, 318 nm, and the duty cycle is 0.45, to ensure that the coupling loss of the grating coupler 122 at a wavelength of 1550 nm is less than 0.22 dB, while ensuring that the coupling efficiency of TE polarized light is greater than 85%. In other embodiments of this application, the angle between the sidewall and the bottom of the grating groove t is less than 90° (e.g., 80°) to reduce back reflection of the grating coupler 122. Optionally, the grating coupler 122 includes a Bragg grating structure.

[0083] It should be noted that the length of the strip waveguide is a multiple of the number of beats in which the 1550nm laser propagates within it, and the period design of the grating coupler must satisfy the Bragg condition for a specific polarization (e.g., TE or TM mode), ensuring that the laser coupled into the strip waveguide is linearly polarized light with good polarization. For example, if the grating coupler achieves efficient coupling only for TE polarized light, while suppressing TM polarized light by more than 25dB, polarization crosstalk in magnetic field measurements can be effectively avoided. Furthermore, it is important to emphasize that the loss during single-mode transmission at 1550nm wavelength in the strip waveguide can be less than 1.2dB / cm.

[0084] See Figure 5 and Figure 6 In one embodiment, during the etching of the functional layer 120 to form the strip waveguide 121 and the grating coupler 122, the strip waveguide 121 includes a sensing waveguide unit 121a and a reference waveguide unit 121b, and the sensing waveguide unit 121a and the reference waveguide unit 121b are parallel to each other and spaced apart; the grating coupler 122 includes a first grating coupler 122a formed at one end of the strip waveguide 121 and a second grating coupler 122b and a third grating coupler 122c formed at the other end of the strip waveguide 121.

[0085] Meanwhile, continue to refer to Figure 5 and Figure 6 In one embodiment, during the etching of functional layer 120 to form strip waveguide 121 and grating coupler 122, beam splitter 123 and multi-mode interferometer 124 are also etched. A beam splitter (MMI) is formed between a first grating coupler 122a and a strip waveguide 121, with the incident end of the beam splitter 123 connected to the first grating coupler 122a and the two output ends of the beam splitter 123 connected to the inductive waveguide unit 121a and the reference waveguide unit 121b, respectively. A multimode interferometer 124 is formed between the strip waveguide 121, the second grating coupler 122b, and the third grating coupler 122c, with the two input ports of the multimode interferometer 124 corresponding to the inductive waveguide unit 121a and the reference waveguide unit 121b, respectively, and the two output ports of the multimode interferometer 124 corresponding to the second grating coupler 122b and the third grating coupler 122c, respectively. Optionally, the beam splitter 123 includes a one-to-two beam splitter; the multimode interferometer 124 includes a 2×4 multimode interferometer.

[0086] Next, refer to Figure 7Two spaced-apart piezoelectric thin films 130 are formed on a strip waveguide 121, with the extension direction of the strip waveguide 121 being the same as that of the piezoelectric thin film 130. Exemplarily, the formation process of the piezoelectric thin film 130 includes: uniformly coating photoresist on the functional layer 120, and performing photolithography and development processes to form a patterned second photoresist layer (not shown in the figure) on the strip waveguide 121, and depositing the piezoelectric thin film 130 on the strip waveguide 121 exposed by the second photoresist layer. Optionally, the piezoelectric thin film 130 is formed using a plasma chemical vapor deposition process, and the material of the piezoelectric thin film 130 includes aluminum nitride (AlN). Optionally, the thickness of the piezoelectric thin film 130 is, for example, 200 nm, and the residual stress of the piezoelectric thin film 130 is less than 100 MPa.

[0087] It should be noted that the piezoelectric film deforms when energized, generating a symmetrical "panda-shaped" dual stress field on both sides of the strip waveguide (the morphology of the stress field can be found in [reference needed]). Figure 13 The semi-circular region below the medium-piezoelectric thin film 130 gives the strip waveguide both a fast and slow axis, and also imparts polarization-maintaining properties. Optionally, the symmetrical spacing between the two stress fields is, for example, 0.5 μm, and the birefringence Δn is greater than 3.5 × 10⁻⁶. −4 .

[0088] Then refer to Figure 8 An optical core layer 140 is formed within the strip waveguide 121. The orthographic projection of the optical core layer 140 onto the plane containing the piezoelectric thin films 130 lies between the two piezoelectric thin films 130, and the optical core layer 140 is equidistant from the two piezoelectric thin films 130, thus forming a polarization-maintaining waveguide structure comprising the strip waveguide 121, the piezoelectric thin films 130, and the optical core layer 140. Optionally, the crosstalk suppression of the polarization-maintaining waveguide structure is less than 0.15 dB / cm.

[0089] In one embodiment, the formation process of the optical core layer includes: forming a third photoresist layer with an opening on the functional layer, the opening exposing the region in the strip waveguide where the optical core layer will be formed (i.e., the center of the panda-shaped stress field generated by the two piezoelectric films in the strip waveguide); depositing a mixed molten salt of thallium nitrate (TlNO3) and potassium nitrate (KNO3) on the strip waveguide exposed by the opening; injecting thallium ions as source ions into the strip waveguide to increase the waveguide refractive index of the injected portion and form a preliminary ion implantation region in the strip waveguide (the preliminary ion implantation region formed by thallium ion implantation is the basis for the subsequent formation of the optical core layer). Optionally, the ratio of thallium nitrate to potassium nitrate in the mixed molten salt is, for example, 1:3 (mol%), the process temperature range includes 380°C to 390°C, and the process time is, for example, 15 min. In other embodiments of this application, the specific range of the process parameters described above can be adjusted according to actual needs, and this application does not limit this.

[0090] In one embodiment, during the formation of the optical core layer in the inductive waveguide unit, terbium chloride can be added to the mixed molten salt as described above, so that the subsequently formed optical core layer is doped with terbium ions to achieve the effect of inducing a magnetic field. It should be emphasized that by forming an optical core layer simultaneously doped with thallium ions and terbium ions, not only can the local refractive index be effectively improved, but the strong magneto-optical effect of the optical core layer can also work synergistically with the functional layer, resulting in a much higher-than-expected improvement in the magneto-optical sensitivity of the entire polarization-maintaining waveguide structure.

[0091] Accordingly, in one embodiment, when forming an optical core layer simultaneously doped with thallium ions and terbium ions in the inductive waveguide unit, only thallium ions are doped in the optical core layer formed in the reference waveguide unit, so as to avoid magneto-optical effect in the optical core layer in the reference waveguide unit.

[0092] It should be noted that after forming the initial ion implantation region, an electric field-assisted ion exchange power supply and two electric field-assisted ion exchange electrode plates are provided. These two electrode plates are placed on the upper and lower surfaces of the silicon wafer, respectively, and the electric field-assisted ion exchange power supply is used to energize them, promoting source ion exchange within the ion implantation region. This expands the area and cross-sectional radius of the ion implantation region, forming an optical core layer within the strip waveguide. Finally, the two electric field-assisted ion exchange electrode plates are removed. Optionally, during ion exchange using the electric field-assisted ion exchange electrode plates, the electric field strength can be, for example, 150 V / cm, to increase the diameter of the optical core layer, thereby enhancing the magneto-optical interaction length.

[0093] For example, before the ion exchange process, the diameter of the optical core layer is, for example, 3.5 μm and the refractive index increment Δn is greater than 0.03. After the ion exchange process, the diameter of the optical core layer is expanded to 5.2 μm and the magneto-optical interaction length is increased by 40% on the original basis (i.e., the case before the ion exchange process).

[0094] See Figures 9 to 11 In one embodiment, after forming the optical core layer 140, the method for manufacturing the silicon photonic integrated magneto-optical sensor chip further includes: (See reference) Figure 9 A first insulating encapsulation layer 150 is formed on the functional layer 120, the piezoelectric film 130, and the optical core layer 140; see reference. Figure 10 A quantum dot laser 160 and a photodetector 170 are formed on the first insulating encapsulation layer 150, and the orthographic projection of the quantum dot laser 160 toward the substrate 100 is coupled to a grating coupler 122 (i.e., Figure 6The orthographic projection of the first grating coupler 122a towards the substrate 100 at least partially coincides with the orthographic projection of the second grating coupler 122a towards the substrate 100. Two photodetectors 170 are included, and the orthographic projections of the two photodetectors 170 towards the substrate 100 at least partially coincide with the orthographic projections of different grating couplers 122a towards the substrate 100 (i.e., the two photodetectors 170 respectively coincide with...). Figure 6 The second grating coupler 122b and the third grating coupler 122c in the figure at least partially overlap); see also Figure 11 A second insulating encapsulation layer 180 is formed on the first insulating encapsulation layer 150, covering the quantum dot laser 160 and the photodetector 170; a first electrical connector 181 is formed within the first insulating encapsulation layer 150 and the second insulating encapsulation layer 180.

[0095] Continue reading Figure 9 and Figure 10 In one embodiment, a layer of BCB adhesive is spin-coated onto the functional layer 120, the piezoelectric film 130, and the optical core layer 140, and pre-cured to form a first insulating encapsulation layer 150. A quantum dot laser 160 and a photodetector 170 are placed on the first insulating encapsulation layer 150 above the grating coupler 122 and pre-bonded to ensure that the laser emitted by the quantum dot laser 160 can be well coupled into the functional layer 120, and that the photodetector 170 can well receive the light waves emitted from the functional layer 120 via the grating coupler 122. Subsequently, a low-temperature annealing process is performed to bond the quantum dot laser 160 and the photodetector 170 to the first insulating encapsulation layer 150. Optionally, the wavelength of the quantum dot laser 160 is, for example, 1550 nm, the output power is, for example, 15 mW, and the linewidth is less than 100 kHz.

[0096] It should be noted that, for reference Figure 6 , Figure 11 and Figure 12In one embodiment, the quantum dot laser 160 emits a laser beam, which is then converted into linearly polarized light after passing through the first grating coupler 122a and enters the beam splitter 123. The beam splitter 123 splits the linearly polarized light in a 1:1 ratio and sends the split linearly polarized light into the inductive waveguide unit 121a and the reference waveguide unit 121b, respectively. At this time, the linearly polarized light passing through the inductive waveguide unit 121a is the signal light, and the linearly polarized light passing through the reference waveguide unit 121b is the reference light. The signal light and the reference light are simultaneously sent into the multimode interferometer 124 from two input ports, causing the reference light and the signal light to interfere inside the multimode interferometer 124 and generating four light intensity signals at the output port of the multimode interferometer 124. Optionally, the wavelength of the laser beam is 1550 nm; the length of the multimode interference region in the multimode interferometer 124 is, for example, 95 μm, the width of the multimode interference region (i.e., the MMI region) is, for example, 12 μm, the width of the access waveguide is, for example, 500 nm, the input / input waveguide spacing is, for example, 3 μm, and the tapered waveguide length is, for example, 20 μm, so as to achieve an adiabatic transition by connecting the narrow access waveguide and the wide multimode interference region, thereby maximizing the effect of reducing reflection and mode mismatch.

[0097] It should be noted that the four optical intensity signals mentioned above are the result of constructive and destructive interference between the reference light and the signal light, and the phase relationships between the four optical intensity signals are fixed at 0°, 180° (in-phase I-channel signal), 90°, and 270° (quadrature Q-channel signal). See further... Figure 6 , Figure 11 and Figure 12 In subsequent data processing, of the four light intensity signals described above, the Q-channel signal is output from one output port of the multimode interferometer 124, passes through the second grating coupler 122b, and is transmitted to one of the photodetectors 170. The I-channel signal is output from another output port of the multimode interferometer 124, passes through the third grating coupler 122c, and is transmitted to another photodetector 170. The two photodetectors 170 convert the received light intensity signals (i.e., the Q-channel signal and the I-channel signal) into differential electrical signals, thereby eliminating common-mode noise and extracting the Q-channel and I-channel electrical signals containing magnetic field information. Optionally, in subsequent signal processing, the Q-channel and I-channel electrical signals can be input into a signal processing circuit to accurately calculate the phase change of the signal light relative to the reference light, thereby obtaining the magnetic field strength.

[0098] Continue reading Figure 11In one embodiment, the process of forming the second insulating encapsulation layer 180 and the first electrical connector 181 includes: further spin-coating BCB adhesive onto the first insulating encapsulation layer 150, the quantum dot laser 160, and the photodetector 170, and performing a pre-curing treatment to form the second insulating encapsulation layer 180; forming through-holes (not shown in the figure) in the first and second insulating encapsulation layers 150 and 180 using an etching process, and filling the through-holes with metal material to form the first electrical connector 181. Optionally, the material of the first electrical connector 181 includes tungsten, aluminum, copper, and other common metal or alloy materials. Optionally, the through-holes are formed in the first and second insulating encapsulation layers 150 and 180 using a Bosch process. Optionally, the pre-curing process temperature is, for example, 125°C, and the process time is, for example, 5 minutes.

[0099] Continue reading Figure 11 In one embodiment, after forming the first electrical connector 181, the method for manufacturing the silicon photonic integrated magneto-optical sensor chip further includes: providing a wafer W2, the wafer W2 including a substrate 200 and a semiconductor structure 210 formed on the substrate 200; forming a second electrical connector 201 within the substrate 200; and bonding the wafer W2 to a silicon wafer W1, such that the substrate 200 is bonded to the side of the second insulating encapsulation layer 180 away from the substrate 100, and the first electrical connector 181 and the second electrical connector 201 are connected. Optionally, the semiconductor structure 210 includes a CMOS circuit structure. Optionally, the process temperature during bonding is, for example, 180°C, the process pressure is, for example, 1.5 MPa, and the alignment accuracy of the wafer W2 and the silicon wafer W1 is within ±0.25 μm.

[0100] In one embodiment, a via is formed in the substrate using a Bosch process, and copper or tungsten is electroplated into the via to fill it and form a second electrical connector. Optionally, SF6 and C3F7 can be used alternately for etching during the formation of the via in the substrate using the Bosch process. Optionally, the diameter of the via ranges from 5 μm to 50 μm, and the aspect ratio of the via is, for example, 10:1. Optionally, the resistivity of the second electrical connector is less than 5 Ω·cm. .

[0101] It should be noted that the first electrical connector is used to bring out the polarization-maintaining waveguide structure, quantum dot laser, and photodetector within the silicon wafer, while the second electrical connector is used to bring out the semiconductor structure within the wafer. Therefore, when bonding the wafer to the silicon wafer, the first and second electrical connectors are aligned one by one in a direction perpendicular to the substrate surface to achieve a vertical electrical connection between the silicon wafer and the wafer.

[0102] Accordingly, this application also provides a silicon photonic integrated magneto-optical sensing chip. Figure 13 for Figure 11 The strip waveguide 121 in the silicon photonic integrated magneto-optical sensing chip shown (e.g.) Figure 6 A schematic cross-sectional view of the inductive waveguide unit 121a), and Figure 13 The corresponding cross-section is perpendicular to the extension direction of the strip waveguide 121. See [reference needed]. Figure 11 and Figure 13 One embodiment of this application provides a silicon photonic integrated magneto-optical sensing chip including a silicon wafer W1. The silicon wafer W1 includes a substrate 100, a buffer layer 110, a functional layer 120, and a polarization-maintaining waveguide structure. The buffer layer 110 is located on the substrate 100, and the functional layer 120 is located on the buffer layer 110. The functional layer 120 includes a strip waveguide 121 and a grating coupler 122, with the grating coupler 122 located on both sides of the strip waveguide 121. The polarization-maintaining waveguide structure includes a strip waveguide 121... The waveguide 121, two spaced-apart piezoelectric thin films 130, and an optical core layer 140 are provided. The piezoelectric thin film 130 is located on the strip waveguide 121, and the extension direction of the piezoelectric thin film 130 is the same as the extension direction of the strip waveguide 121. The optical core layer 140 is located inside the strip waveguide 121, and the orthographic projection of the optical core layer 140 onto the plane containing the piezoelectric thin film 130 is located between the two piezoelectric thin films 130. The optical core layer 140 is equidistant from the two piezoelectric thin films 130.

[0103] As described above, the silicon photonic integrated magneto-optical sensing chip forms a strip waveguide within the functional layer, two spaced-apart piezoelectric thin films on the strip waveguide, and an optical core layer within the strip waveguide. This causes the piezoelectric thin films to deform when energized, generating symmetrical panda-shaped stress fields on both sides of the strip waveguide. This forms a polarization-maintaining waveguide structure comprising a strip waveguide, piezoelectric thin films, and an optical core layer, effectively improving the polarization stability and integration of the silicon photonic integrated magneto-optical sensing chip.

[0104] Continue reading Figure 11 and Figure 13 In one embodiment, grating couplers 122 are located on both sides of the strip waveguide 121 along an extension direction perpendicular to the strip waveguide 121. Optionally, the grating coupler 122 includes a plurality of grating grooves t that are parallel to each other and spaced apart within the functional layer 120, and the extension direction of the grating grooves t is perpendicular to the extension direction of the strip waveguide 121.

[0105] Continue reading Figure 11 and Figure 13 In one embodiment, both the piezoelectric film 130 and the optical core layer 140 are strip-shaped structures, and the piezoelectric film 130, the optical core layer 140, and the strip waveguide 121 all extend in the same direction. Optionally, when the piezoelectric film 130 is energized, the strip waveguide 121 below the piezoelectric film 130 includes a dual stress field symmetrically distributed around the optical core layer 140 (see [reference]). Figure 13(The semi-circular area in the middle).

[0106] See Figure 6 and Figure 11 In one embodiment, the strip waveguide 121 includes a sensing waveguide unit 121a and a reference waveguide unit 121b, and the sensing waveguide unit 121a and the reference waveguide unit 121b are parallel to each other and spaced apart; the grating coupler 122 includes a first grating coupler 122a located at one end of the strip waveguide 121 and a second grating coupler 122b and a third grating coupler 122c located at the other end of the strip waveguide 121.

[0107] Continue reading Figure 6 and Figure 11 In one embodiment, the functional layer 120 further includes a beam splitter 123 and a multi-mode interference coupler (MMI); wherein the beam splitter 123 is located between the first grating coupler 122a and the strip waveguide 121, and the incident end of the beam splitter 123 is connected to the first grating coupler 122a, and the two output ends of the beam splitter 123 are respectively connected to the inductive waveguide unit 121a and the reference waveguide unit 121b; the multi-mode interferometer 124 is located between the strip waveguide 121 and the second grating coupler 122b and the third grating coupler 122c, and the two input ports of the multi-mode interferometer 124 correspond to the inductive waveguide unit 121a and the reference waveguide unit 121b, respectively, and the two output ports of the multi-mode interferometer 124 correspond to the second grating coupler 122b and the third grating coupler 122c, respectively. Optionally, the beam splitter 123 includes a one-to-two beam splitter; the multimode interferometer 124 includes a 2×4 multimode interferometer.

[0108] In one embodiment, the substrate includes a silicon-on-insulator substrate, the buffer layer is made of silicon oxide, the functional layer is made of silicon nitride, and the piezoelectric film is made of aluminum nitride. Optionally, when the strip waveguide includes an inductive waveguide unit and a reference waveguide unit, the implanted ions corresponding to the optical core layer in the inductive waveguide unit include thallium ions and terbium ions to effectively improve the local refractive index, so that the strong magneto-optical effect of the optical core layer and the functional layer can work synergistically; while the implanted ions corresponding to the optical core layer in the reference waveguide unit only include thallium ions to avoid magneto-optical effects in the optical core layer of the reference waveguide unit.

[0109] Continue reading Figure 11In one embodiment, the silicon photonic integrated magneto-optical sensing chip further includes a first insulating encapsulation layer 150, a quantum dot laser 160, a photodetector 170, a second insulating encapsulation layer 180, and a first electrical connector 181; wherein, the first insulating encapsulation layer 150 is located on the functional layer 120, the piezoelectric thin film 130, and the optical core layer 140, the quantum dot laser 160 is located on the first insulating encapsulation layer 150, and the orthographic projection of the quantum dot laser 160 toward the substrate 100 is coupled to a grating coupler 122 (i.e., Figure 6 The orthographic projection of the first grating coupler 122a towards the substrate 100 at least partially coincides with that of the first insulating encapsulation layer 150; the photodetector 170 is located on the first insulating encapsulation layer 150, and the orthographic projection of the photodetector 170 towards the substrate 100 at least partially coincides with the orthographic projection of the grating coupler 122a towards the substrate 100 (when there are two photodetectors 170, the orthographic projections of the two photodetectors 170 towards the substrate 100 respectively coincide with the orthographic projection of the grating coupler 122a towards the substrate 100). Figure 6 The second grating coupler 122b and the third grating coupler 122c in the first insulating encapsulation layer 150 have at least partially overlapping orthogonal projections toward the substrate 100. The second insulating encapsulation layer 180 is located on the first insulating encapsulation layer 150 and covers the quantum dot laser 160 and the photodetector 170. The first electrical connector 181 is located within the first insulating encapsulation layer 150 and the second insulating encapsulation layer 180 and is used to lead out the piezoelectric film 130, the quantum dot laser 160 and the photodetector 170.

[0110] See Figure 11 In one embodiment, the silicon photonic integrated magneto-optical sensing chip further includes a wafer W2, which includes a substrate 200 and a semiconductor structure 210 formed on the substrate 200; a second electrical connector 201 is located within the substrate 200 and is used to bring out the semiconductor structure; wherein the wafer W2 and the silicon wafer W1 are bonded, the substrate 200 is located on a second insulating encapsulation layer 180, and the first electrical connector 181 and the second electrical connector 201 are connected.

[0111] It should be noted that the first electrical connector is used to bring out the polarization-maintaining waveguide structure, quantum dot laser, and photodetector within the silicon wafer, while the second electrical connector is used to bring out the semiconductor structure within the wafer. Therefore, when bonding the wafer to the silicon wafer, the first and second electrical connectors are aligned one by one in a direction perpendicular to the substrate surface to achieve a vertical electrical connection between the silicon wafer and the wafer.

[0112] In one embodiment, the silicon photonic integrated magneto-optical sensing chip described above can be integrated onto a microfluidic chip in a flow cytometry cell sorting device to monitor the magnetic field strength and distribution in real time, ensuring the precision of the magnetic field in manipulating cells, thereby helping to improve the efficiency and accuracy of cell sorting.

[0113] It should be noted that, as described above, the silicon photonics integrated magneto-optical sensing chip can provide high-precision measurement data for the magnetic field feedback control of the on-chip magnetocontrol system, realizing closed-loop control of the magnetic field, thereby enhancing the stability and reliability of magnetic field manipulation and meeting the requirements for precise cell manipulation in flow cytometry sorting. Furthermore, the silicon photonics integrated magneto-optical sensing chip provided in this application is compatible with microfluidic platforms, which helps to achieve miniaturization and integration of flow cytometry sorting equipment, reduces equipment costs, improves equipment portability and ease of use, and effectively expands the application scenarios of silicon photonics integrated magneto-optical sensing chips in biomedical research and clinical diagnosis.

[0114] In other embodiments of this application, the silicon photonic integrated magneto-optical sensing chip described above can also be disposed in other devices or apparatuses to meet different application requirements. Computationalists in the art can adapt it according to actual needs, and this application does not impose any restrictions on it.

[0115] In summary, this application provides a silicon photonics integrated magneto-optical sensing chip and its manufacturing method. By forming a strip waveguide within a functional layer, and then forming two spaced-apart piezoelectric thin films on the strip waveguide, with the extension directions of the strip waveguide and the piezoelectric thin films being the same, and forming an optical core layer within the strip waveguide, the orthographic projection of the optical core layer onto the plane containing the piezoelectric thin films lies between the two piezoelectric thin films, and the distance between the optical core layer and the two piezoelectric thin films is the same. This causes the piezoelectric thin films to deform when energized, generating symmetrical panda-shaped stress fields on both sides of the strip waveguide, thereby forming a polarization-maintaining waveguide structure including the strip waveguide, the piezoelectric thin films, and the optical core layer. This effectively improves the polarization stability and integration density of the silicon photonics integrated magneto-optical sensing chip.

[0116] In the description of this specification, the references to terms such as "some embodiments," "other embodiments," "ideal embodiments," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example that are included in at least one embodiment or example of this application. In this specification, the illustrative descriptions of the above terms do not necessarily refer to the same embodiments or examples.

[0117] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features of the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0118] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A method for manufacturing a silicon photonic integrated magneto-optical sensor chip, characterized in that, include: A silicon wafer is provided, and a buffer layer is formed on the substrate of the silicon wafer; A functional layer is formed on the buffer layer; The functional layer is etched to form a strip waveguide and a grating coupler within the functional layer, with the grating coupler located on both sides of the strip waveguide; Two piezoelectric thin films spaced apart are formed on the strip waveguide, and the extension direction of the strip waveguide is the same as the extension direction of the piezoelectric thin films. An optical core layer is formed within the strip waveguide, and the optical core layer is equidistant from the two piezoelectric films, to form a polarization-maintaining waveguide structure comprising the strip waveguide, the piezoelectric films, and the optical core layer; A first insulating encapsulation layer is formed on the functional layer, the piezoelectric film, and the optical core layer; A quantum dot laser and a photodetector are formed on the first insulating encapsulation layer, and the orthographic projection of the quantum dot laser toward the substrate at least partially coincides with the orthographic projection of one of the grating couplers toward the substrate, and the orthographic projection of the photodetector toward the substrate at least partially coincides with the orthographic projection of another of the grating couplers toward the substrate. A second insulating encapsulation layer is formed on the first insulating encapsulation layer to cover the quantum dot laser and the photodetector; A first electrical connection is formed within the first insulating encapsulation layer and the second insulating encapsulation layer; After forming the first electrical connection, the method further includes: A wafer is provided, the wafer including a substrate and a semiconductor structure formed on the substrate; A second electrical connection is formed within the substrate; The wafer is bonded to the silicon wafer, such that the substrate is bonded to the side of the second insulating encapsulation layer away from the substrate, and the first electrical connector and the second electrical connector are connected.

2. A silicon photonic integrated magneto-optical sensing chip, characterized in that, include: Silicon wafer, the silicon wafer including a substrate; A buffer layer is located on the substrate; A functional layer is located on the buffer layer. The functional layer includes a strip waveguide and a grating coupler, with the grating coupler located on both sides of the strip waveguide. The polarization-maintaining waveguide structure includes the strip waveguide, two spaced-apart piezoelectric thin films, and an optical core layer; wherein, The piezoelectric thin film is located on the strip waveguide, and the extension direction of the piezoelectric thin film is the same as the extension direction of the strip waveguide; The optical core layer is located inside the strip waveguide. The orthographic projection of the optical core layer onto the plane containing the piezoelectric thin film is located between the two piezoelectric thin films, and the optical core layer is at the same distance from the two piezoelectric thin films. A first insulating encapsulation layer is located on the functional layer, the piezoelectric film, and the optical core layer; A quantum dot laser is located on the first insulating encapsulation layer, wherein the orthographic projection of the quantum dot laser toward the substrate at least partially coincides with the orthographic projection of the grating coupler toward the substrate; A photodetector is located on the first insulating encapsulation layer, and the orthographic projection of the photodetector toward the substrate at least partially coincides with the orthographic projection of the other grating coupler toward the substrate; A second insulating encapsulation layer is located on the first insulating encapsulation layer and covers the quantum dot laser and the photodetector; A first electrical connector, located within the first and second insulating encapsulation layers, is used to bring out the piezoelectric thin film, the quantum dot laser, and the photodetector.

3. The silicon photonic integrated magneto-optical sensing chip according to claim 2, characterized in that, Both the piezoelectric thin film and the optical core layer have a strip-shaped structure, and the piezoelectric thin film, the optical core layer and the strip waveguide all extend in the same direction.

4. The silicon-photon integrated magneto-optical sensing chip according to claim 2 or 3, characterized in that, Along the extension direction perpendicular to the strip waveguide, the grating coupler is located on both sides of the strip waveguide; The grating coupler includes a plurality of grating grooves that are parallel to each other and spaced apart within the functional layer, and the extending direction of the grating grooves is perpendicular to the extending direction of the strip waveguide.

5. The silicon-photon integrated magneto-optical sensing chip according to claim 2 or 3, characterized in that, When the piezoelectric film is energized, the strip waveguide beneath the piezoelectric film includes a dual stress field symmetrically distributed around the optical core layer.

6. The silicon-photon integrated magneto-optical sensing chip according to claim 2, characterized in that, The substrate includes a silicon-on-insulator substrate, the material of the functional layer includes terbium-doped silicon nitride, the material of the piezoelectric thin film includes aluminum nitride, and the implanted ions in the optical core layer include thallium ions.

7. The silicon-photon integrated magneto-optical sensing chip according to claim 2, characterized in that, The silicon photonic integrated magneto-optical sensing chip also includes: A wafer, including a substrate and a semiconductor structure formed on the substrate; A second electrical connector, located within the substrate, is used to bring out the semiconductor structure; The wafer and the silicon wafer are bonded together, the substrate is located on the second insulating encapsulation layer, and the first electrical connector and the second electrical connector are connected.

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