CN116837463A - Preparation method of modulation device based on silicon carbide and modulation device - Google Patents

Abstract

The application relates to the technical field of information functional materials, in particular to a preparation method of a modulation device based on silicon carbide and the modulation device. The method comprises the following steps: preparing an epitaxial silicon carbide film layer on a silicon carbide epitaxial substrate; heavily doping a preset area in the epitaxial silicon carbide film layer, and preparing a modulation device structure in the heavily doped area; preparing a first device protection layer, and bonding a first supporting substrate and the first device protection layer; removing the silicon carbide epitaxial substrate; and bonding the second support substrate with the modulation device structure, and removing the first support substrate and the first device protection layer to obtain the modulation device based on silicon carbide. The preset area in the epitaxial silicon carbide film layer is heavily doped, and the modulation device structure is prepared in the heavily doped area, so that the high-efficiency and high-speed optical modulation of the silicon carbide in the integrated optical system can be realized based on a carrier dispersion mechanism.

Description

A silicon carbide-based modulation device preparation method and modulation device

Technical field

The present application relates to the technical field of information functional materials, and in particular to a silicon carbide-based modulation device preparation method and modulation device.

Background technique

As a representative material in the third generation of semiconductors, silicon carbide (SiC) combines high physical strength (Mohs hardness 9.5, Knoop hardness 2480kg/mm ² ), high thermal conductivity (480W/mK), high corrosion resistance, High melting point, high optical second-order and third-order nonlinear coefficients, wide light transmission window (0.37μm-5.6μm), wide-area defect luminescence window (visible light to mid-infrared), wide bandgap (2.4eV-3.2eV) and many other aspects Excellent features in one. Among them, high refractive index can achieve high restriction of optical modes and will bring greater flexibility in the field of dispersion. The wide bandgap minimizes light absorption losses at high powers, the high second and third orders make silicon carbide excellent in nonlinear optical applications, and the wide defect emission window makes it an ideal material for use as a light source. Therefore, silicon carbide is an ideal material for integrated optical, nonlinear optics, and optomechanical devices.

However, there are many limitations in the application of silicon carbide in integrated optics. On the one hand, silicon carbide needs to be used in the form of single-crystal thin films in integrated optics. However, due to the difficulty in preparing high-quality silicon carbide single crystal thin films, this has caused difficulties in the preparation of silicon carbide thin films for integrated optical applications. On the other hand, silicon carbide has a weak electro-optical effect, which makes it difficult to achieve efficient and high-speed light modulation in integrated optical systems.

Contents of the invention

In order to solve the above technical problems, this application provides a silicon carbide-based modulation device preparation method and modulation device. By preparing an epitaxial silicon carbide film layer on a silicon carbide epitaxial substrate, silicon carbide thin film preparation in integrated optical applications is realized; By heavily doping the preset area in the epitaxial silicon carbide film layer and preparing the modulation device structure in the heavily doped area, it is possible to achieve high efficiency and high efficiency of silicon carbide in integrated optical systems based on the mechanism of carrier dispersion. High-speed light modulation.

In a first aspect, embodiments of the present application disclose a method for preparing a silicon carbide-based modulation device. The method includes:

Obtain silicon carbide epitaxial substrate;

Preparing an epitaxial silicon carbide thin film layer on a silicon carbide epitaxial substrate;

The preset area in the epitaxial silicon carbide film layer is heavily doped to obtain a heavily doped area;

Preparing a modulation device structure in a heavily doped region; the modulation device structure includes opposite first surfaces and second surfaces, the first surface is close to the silicon carbide epitaxial substrate, and the second surface is away from the silicon carbide epitaxial substrate;

preparing a first device protective layer on the second surface;

Obtain a first support substrate, and bond the first support substrate to the first device protective layer to obtain a first bonding structure;

removing the silicon carbide epitaxial substrate in the first bonding structure and exposing the first surface;

Obtain a second support substrate, and bond the second support substrate to the first surface to obtain a second bonding structure;

The first supporting substrate in the second bonding structure and the first device protective layer in the second bonding structure are removed to expose the second surface to obtain a modulation device based on silicon carbide.

In some optional embodiments, obtaining a silicon carbide epitaxial substrate includes:

Obtain silicon carbide substrate;

Perform ion implantation into the silicon carbide substrate to form a defect layer in the silicon carbide substrate;

Obtain a third support substrate, and bond the silicon carbide substrate to the third support substrate to obtain a third bonding structure;

The third bonding structure is heat treated to peel off the silicon carbide substrate in the third bonding structure along the defect layer to obtain a silicon carbide epitaxial substrate bonded to the third support substrate.

In some optional embodiments, the third support substrate is made of silicon carbide or sapphire.

In some optional embodiments, the epitaxial silicon carbide film layer is a lightly doped epitaxial silicon carbide film layer, and the doping concentration of the epitaxial silicon carbide film layer is 1E ¹³ /cm ³ -1E ¹⁵ /cm ³ . The epitaxial silicon carbide film layer The thickness of layer (204) ranges from 400nm to 1500nm.

In some optional embodiments, the size of the heavily doped region is 2.2 μm-101 μm, and the thickness of the heavily doped region is less than or equal to the thickness of the epitaxial silicon carbide film layer.

In some optional embodiments, the modulation device structure is prepared in a heavily doped region, including:

Use photolithography to etch the modulation device structure in the heavily doped region; the etching depth is 200nm-1300nm, and is less than or equal to the thickness of the heavily doped region.

In some optional embodiments, the modulation device structure includes a first preset area, a second preset area and a spacing area, and the spacing area is provided between the first preset area and the second preset area; in the second preset area Preparing a first device protective layer on the surface;

Previously, methods also included:

Perform regional doping on the first preset region according to the first doping type to obtain the first electrode region;

Perform regional doping on the second preset region according to the second doping type to obtain a second electrode region; wherein the first doping type is opposite to the second doping type;

The first electrode area, the second electrode area and the spacer area are activated to obtain an activated modulation device.

In some optional embodiments, the size of the first preset area is 1 μm-50 μm, the size of the second preset area is 1 μm-50 μm, and the size of the spacing area is 200 nm-1000 nm.

In some optional embodiments, the first support substrate in the second bonding structure and the first device protective layer in the second bonding structure are removed to expose the second surface to obtain silicon carbide-based modulation. Devices, including:

removing the first supporting substrate in the second bonding structure and the first device protective layer in the second bonding structure to expose the second surface to obtain the first device structure;

Prepare a first metal electrode in the first electrode region in the first device structure, and prepare a second metal electrode in the second electrode region in the first device structure, to obtain a second device structure;

A second device protective layer is prepared on the second surface in the second device structure to obtain a modulation device based on silicon carbide.

In a second aspect, embodiments of the present application disclose a silicon carbide-based modulation device, which is prepared by the silicon carbide-based modulation device preparation method as described above; the modulation device includes: a second support substrate and Epitaxial silicon carbide thin film layer;

The epitaxial silicon carbide film layer is disposed on the second support substrate;

A heavily doped region is provided in the epitaxial silicon carbide film layer;

A modulation device structure is provided in the heavily doped region.

The technical solutions provided by the embodiments of this application have the following technical effects:

The silicon carbide-based modulation device preparation method and modulation device described in the embodiments of the present application realize the preparation of silicon carbide thin films in integrated optical applications by preparing an epitaxial silicon carbide film layer on a silicon carbide epitaxial substrate; through the epitaxial silicon carbide The preset area in the thin film layer is heavily doped to obtain a heavily doped area, and then the modulation device structure is prepared in the heavily doped area, so that the silicon carbide can be used in the integrated optical system based on the mechanism of carrier dispersion. Efficient, high-speed light modulation. In addition, by obtaining the first support substrate and combining the first support substrate and the second support substrate, the modulation device structure is transferred to the second support substrate to reduce the cost of the silicon carbide single piece and facilitate the carbonization-based Large-scale promotion and application of silicon modulation devices.

Description of the drawings

In order to more clearly explain the technical solutions and advantages in the embodiments of the present application or the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings in the following description The drawings are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without exerting creative efforts.

Figure 1 is a schematic flow chart of a silicon carbide-based modulation device preparation method provided by an embodiment of the present application;

Figure 2a is a schematic structural diagram of a high-quality silicon carbide substrate provided by an embodiment of the present application;

Figure 2b is a schematic structural diagram of a high-quality silicon carbide substrate after ion implantation according to an embodiment of the present application;

Figure 2c is a schematic diagram of structural changes for surface treatment of a low-cost silicon carbide substrate according to an embodiment of the present application;

Figure 2d is a schematic structural diagram of a third bonding structure provided by an embodiment of the present application;

Figure 2e is a schematic structural diagram of a silicon carbide epitaxial substrate provided by an embodiment of the present application;

Figure 2f is a schematic structural diagram of a heavily doped epitaxial silicon carbide film layer provided by an embodiment of the present application;

Figure 2g is a schematic structural diagram of a heavily doped region after etching according to an embodiment of the present application;

Figure 2h is a schematic structural diagram of a heavily doped region after etching according to an embodiment of the present application;

Figure 2i is a schematic structural diagram after preparing a first device protective layer according to an embodiment of the present application;

Figure 2j is a schematic structural diagram of a first device protective layer after planarization according to an embodiment of the present application;

Figure 2k is a schematic structural diagram after bonding the first support substrate provided by the embodiment of the present application;

Figure 2l is a schematic structural diagram after removing the silicon carbide epitaxial substrate provided by the embodiment of the present application;

Figure 2m is a schematic structural diagram after bonding the second support substrate provided by the embodiment of the present application;

Figure 2n is a schematic structural diagram after removing the silicon layer in the first support substrate provided by an embodiment of the present application;

Figure 2o is a schematic structural diagram after removing the first support substrate and the first device protective layer according to an embodiment of the present application;

Figure 2p is a schematic structural diagram of a silicon carbide-based modulation device provided by an embodiment of the present application;

FIG. 3 is a schematic structural diagram of a silicon carbide-based modulation device provided by an embodiment of the present application.

The following is a supplementary explanation of the accompanying drawings:

201-High-quality silicon carbide substrate; 202-Defect layer; 203-Low-cost silicon carbide substrate; 204-Epitaxial silicon carbide film layer; 205-Heavily doped area; 206-First preset area; 207-Second Preset area; 208-spacing area; 209-first electrode area; 210-second electrode area; 211-first device protective layer; 212-first support substrate; 213-second support substrate; 214-th A metal electrode; 215-a second metal electrode; 216-a second device protective layer.

Detailed ways

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of this application.

It should be noted that “one embodiment” or “embodiment” referred to in the description of the embodiments of this application refers to specific features, structures or characteristics that may be included in at least one implementation of this application. It should be understood that in the description and claims of the embodiments of the present application and the above-mentioned drawings, the directions or positional relationships indicated by terms such as "upper", "lower", "top" and "bottom" are based on those shown in the drawings. The orientation or positional relationship shown is only to facilitate the description of the present application and simplify the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present application. limit. The terms “first” and “second” are used for descriptive purposes only and shall not be understood as indicating or implying relative importance or implicitly indicating the quantity of indicated technical features. Therefore, features defined as “first” and “second” may explicitly or implicitly include one or more of these features. Furthermore, the terms "first", "second", etc. are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It is to be understood that the data so used are interchangeable under appropriate circumstances so that the embodiments of the application described herein can be practiced in sequences other than those illustrated or described herein. Furthermore, in the description of this embodiment, unless otherwise specified, "plurality" means two or more. Furthermore, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, e.g., a process, method, system or product that encompasses a series of steps or units need not be limited to those steps that are expressly listed. or units, but may include other steps or units not expressly listed or inherent to such processes, methods, products or devices.

In order to make the purpose, technical solutions and advantages disclosed in the embodiments of the present application clearer, the embodiments of the present application will be further described in detail below in conjunction with the drawings and examples. It should be understood that the specific embodiments described here are only used to explain the embodiments of the present application and are not used to limit the embodiments of the present application.

Silicon carbide materials have more than 200 crystal forms, among which 3C-SiC, 4H-SiC and 6H-SiC are the most widely used. 3C-SiC mainly uses atmospheric pressure chemical vapor deposition (Amospheric Pressure Chemical Vapor Deposition, APCVD) and reduced pressure chemical vapor deposition (Reduced Pressure Chemical Vapor Deposition, RPCVD) methods to deposit a silicon carbide film on the surface of a silicon (Si) substrate. . The 3C-SiC film prepared by this method is mainly a polycrystalline film, and the crystal quality cannot reach single crystal. Moreover, for 4H-SiC and 6H-SiC, their growth temperature is greater than the melting point temperature of silicon, and it is impossible to grow single crystal silicon carbide films on silicon substrates through traditional thin film deposition heteroepitaxial methods. Therefore, this causes difficulties in the growth of silicon carbide films when silicon carbide is used in integrated optics. In addition, silicon carbide has a weak electro-optical effect, which creates great obstacles for the realization of efficient and high-speed light modulation of silicon carbide in integrated optical systems.

In view of this, embodiments of the present application provide a silicon carbide-based modulation device preparation method and a modulation device. By preparing an epitaxial silicon carbide film layer on a silicon carbide epitaxial substrate, silicon carbide thin film preparation in integrated optical applications is realized; By heavily doping a preset area in the epitaxial silicon carbide film layer to obtain a heavily doped area, and then preparing a modulated device structure in the heavily doped area, silicon carbide can be realized based on the mechanism of carrier dispersion. Efficient, high-speed light modulation in integrated optical systems. In addition, by obtaining the first support substrate and combining the first support substrate and the second support substrate, the modulation device structure is transferred to the second support substrate to reduce the cost of the silicon carbide single piece and facilitate the carbonization-based Large-scale promotion and application of silicon modulation devices.

Please refer to Figure 1. Figure 1 is a schematic flow chart of a method for preparing a silicon carbide-based modulation device provided by an embodiment of the present application. As shown in Figure 1, the preparation method includes:

S101: Obtain silicon carbide epitaxial substrate.

In the embodiments of this application, for the manufacture of all silicon carbide electronic devices, diffusion doping cannot be performed in the silicon carbide substrate, and if ions are directly injected into it, the electrical quality of the silicon carbide will be poor, so it is necessary to first The epitaxial film is grown on a silicon carbide substrate. Due to the excellent electrical properties of homoepitaxially grown silicon carbide films, almost all high-performance silicon carbide devices are currently manufactured using this epitaxial film. Therefore, when preparing silicon carbide-based modulation devices, it is first necessary to obtain a silicon carbide epitaxial substrate. The silicon carbide epitaxial substrate serves as the basis for the epitaxial silicon carbide thin film layer 204 and needs to be of high quality. Optionally, the silicon carbide epitaxial substrate may be a high-quality silicon carbide substrate 201. High-quality silicon carbide substrate 201 refers to silicon carbide wafers whose product quality is industrial grade P or selected grade Z in industrial production.

In the embodiments of the present application, when preparing modulation devices based on silicon carbide, the role of the silicon carbide epitaxial substrate is to provide a high-quality silicon carbide single crystal surface, so that high-quality silicon carbide can be grown on the surface during the silicon carbide epitaxial process. Quality epitaxial silicon carbide thin film layer 204. In actual production, the use of high-quality silicon carbide substrate 201 usually requires higher production costs, while the silicon carbide epitaxial substrate only requires a thin layer of silicon carbide film to provide a high-quality silicon carbide single crystal surface to meet the high-quality requirements. Silicon carbide epitaxy is required. Therefore, in order to reduce the production cost, a silicon carbide film can be peeled off on the high-quality silicon carbide substrate 201 to serve as the silicon carbide epitaxial substrate. Specifically, a silicon carbide substrate is obtained. The silicon carbide substrate here is a high-quality silicon carbide substrate 201. The silicon carbide substrate is ion implanted to form a defect layer 202 in the silicon carbide substrate. Obtain a third supporting substrate, and bond the silicon carbide substrate and the third supporting substrate to obtain a third bonding structure. The third bonding structure is heat treated to peel off the silicon carbide substrate in the third bonding structure along the defect layer 202 to obtain a silicon carbide epitaxial substrate bonded to the third support substrate.

In the embodiment of the present application, according to the cutting type of different silicon carbide substrates, in order to achieve better homogeneous epitaxy and obtain a high-quality epitaxial silicon carbide film layer 204, the selected silicon carbide substrate may be an N-type silicon carbide substrate. end. After obtaining the silicon carbide substrate, ion implantation is performed on the silicon carbide substrate to form a defect layer 202 in the silicon carbide substrate. A defect layer 202 is formed in the silicon carbide substrate by ion implantation into the silicon carbide substrate, so that the silicon carbide substrate can be peeled off along the implanted defect layer 202 after heat treatment. The direction of ion implantation is from one surface of the silicon carbide substrate. Optionally, the ion implantation direction may be perpendicular to the implantation surface, or may form a preset angle with the second surface. The ions used in ion implantation include at least one of hydrogen ions, helium ions, and neon ions. Ion implantation can be a single ion implantation or a co-implantation of multiple ions. For example, co-implantation of hydrogen and helium ions is used. When two or more ion co-implantation methods are used, the injection sequence can be adjusted according to actual needs. The depth of ion implantation is determined based on the required thickness of the silicon carbide epitaxial substrate. Optional, the dose of ion implantation is 1E15cm ^-2 -1E18cm ^-2 , and the energy of ion implantation is 20keV-2MeV.

In the embodiment of the present application, after completing the ion implantation into the silicon carbide substrate, a third support substrate is obtained, and the silicon carbide substrate and the third support substrate are bonded to obtain a third bonding structure. The third support substrate is used to support the silicon carbide film peeled off from the silicon carbide substrate. Since the epitaxial silicon carbide film layer 204 needs to be prepared on the silicon carbide epitaxial substrate later, and the silicon carbide epitaxial substrate is disposed on the third support substrate, the third support substrate needs to be able to adapt to the thermal stress during the silicon carbide epitaxial process. To avoid problems such as cracking of the epitaxial layer due to thermal mismatch. At the same time, the third supporting substrate also needs to not cause contamination to the epitaxial silicon carbide film layer 204. Optionally, the third supporting substrate is made of low-cost silicon carbide or sapphire. Low-cost silicon carbide here refers to the use of lower-cost silicon carbide substrates in industrial production, such as silicon carbide substrates with product quality at test grade (Dummy), mixed crystalline silicon carbide substrates, and polycrystalline silicon carbide. substrate etc. When the low-cost silicon carbide substrate 203 is selected as the third support substrate, before bonding the silicon carbide substrate to the third support substrate, the surface of the third support substrate needs to be surface treated to make it The surface is super flat. Optionally, the process flow for surface treatment of the surface of the third support substrate includes: rough grinding, fine grinding, rough polishing, low-energy ion beam irradiation trimming, and fine polishing. After surface treatment, the total thickness variation (TTV) of the third support substrate is less than or equal to 1 μm.

In the embodiment of the present application, after the third bonding structure is obtained, the third bonding structure is heat treated, so that the silicon carbide substrate in the third bonding structure is peeled off along the defect layer 202 to obtain the bonded third support. Silicon carbide epitaxial substrate on substrate. Specifically, the third bonding structure is gradually heated to the peeling temperature. The third bonding structure is heated for a preset time, so that the bonding structure is peeled off along the defect layer 202 under small deformation to obtain a silicon carbide film bonded to the third support substrate. After heating the third bonding structure, the implanted ions are gathered in the high-quality silicon carbide substrate 201 and micro-defects are formed, and then the micro-defects expand laterally, thereby achieving high-quality carbonization in the third bonding structure. The silicon substrate 201 is separated along the implanted defect layer 202 to obtain a silicon carbide film bonded to the third support substrate, and then the surface of the silicon carbide film is processed to obtain a silicon carbide epitaxial substrate. The specific heat treatment temperature and heat treatment duration for heat treatment of the third bonding structure can be determined based on the material and crystal form of high-quality silicon carbide. The surface of the silicon carbide film bonded to the third support substrate can be processed by chemical mechanical polishing, and the surface of the treated silicon carbide film has a roughness of less than or equal to 0.2 nm. The peeling residue obtained after heat treatment of the high-quality silicon carbide substrate 201 can be recycled after treatment, thereby reducing production costs.

S103: Prepare an epitaxial silicon carbide film layer 204 on the silicon carbide epitaxial substrate.

In the embodiment of the present application, after obtaining the silicon carbide epitaxial substrate, the epitaxial silicon carbide film layer 204 can be epitaxially prepared on the silicon carbide epitaxial substrate. Optionally, epitaxial methods include but are not limited to physical vapor transport (PhySiCalVapor Transport, PVT), solution method, high temperature chemical vapor deposition (HTCVD), etc. Optionally, the thickness of the epitaxial silicon carbide film layer 204 is 400nm-1500nm. Optionally, during the homoepitaxial process, the prepared epitaxial silicon carbide thin film layer 204 can also be doped with light doping to introduce carriers into the epitaxial silicon carbide thin film layer 204 to improve carbonization. The electro-optical effect of silicon. Optionally, the doping type of the epitaxial silicon carbide film layer 204 may be N-type doping or P-type doping. Optionally, the doping element used for N-type doping of the epitaxial silicon carbide film layer 204 is nitrogen or phosphorus. The doping element used for P-type doping of the epitaxial silicon carbide thin film layer 204 is boron element or aluminum element. Optionally, after the epitaxial silicon carbide thin film layer 204 is lightly doped, the resulting doping concentration of the epitaxial silicon carbide thin film layer 204 is 1E ¹³ /cm ³ -1E ¹⁵ /cm ³ .

S105: Perform heavy doping on a preset area in the epitaxial silicon carbide film layer 204 to obtain a heavily doped area 205.

In the embodiment of the present application, after the preparation of the epitaxial silicon carbide thin film layer 204 is completed, the preset area in the epitaxial silicon carbide thin film layer 204 is heavily doped to obtain a heavily doped area 205. The heavily doped region 205 is used to prepare the modulation device structure. The preset area refers to a part of the area included in a device unit. In the epitaxial silicon carbide film layer 204, multiple device units can be prepared. Optional, the size of the preset area is 2.2μm-101μm. The doping type of heavy doping is the same as the doping type of light doping when preparing the epitaxial silicon carbide film layer 204 . That is, the doping type for lightly doping the epitaxial silicon carbide film layer 204 is N-type doping. When the preset area in the epitaxial silicon carbide film layer 204 is heavily doped, the doping type used is also N-type. Doping. The doping type for lightly doping the epitaxial silicon carbide film layer 204 is P-type doping. When the preset area in the epitaxial silicon carbide film layer 204 is heavily doped, the doping type used is also P-type doping. miscellaneous. After the epitaxial silicon carbide thin film layer 204 is heavily doped, the resulting doping concentration of the epitaxial silicon carbide thin film layer 204 is 1E15/cm ³ -1E ¹⁷ /cm ³ . When heavily doping the preset region, ion implantation can be used to achieve heavy doping. Optionally, when N-type doping is used to heavily dope the preset region, the implanted ions are nitrogen ions or phosphorus ions. When P-type doping is used to heavily dope the preset area, the ions implanted are boron ions or aluminum ions. Optionally, the depth of the doped ion implantation region is 500 nm to 1500 nm, and the depth of the doping ion implantation region is no greater than the thickness of the epitaxial silicon carbide film layer 204 . That is to say, the size of the finally obtained heavily doped region 205 is 2.2 μm-101 μm, and the thickness of the heavily doped region 205 is 500 nm-1500 nm, which is less than or equal to the thickness of the epitaxial silicon carbide film layer 204 .

S107: Prepare a modulation device structure in the heavily doped region 205; the modulation device structure includes opposite first surfaces and second surfaces, the first surface is close to the silicon carbide epitaxial substrate, and the second surface is far away from the silicon carbide epitaxial substrate.

In this embodiment of the present application, after the preset region in the epitaxial silicon carbide film layer 204 is heavily doped, a modulation device structure can be prepared in the resulting heavily doped region 205 . When processing the modulation device structure, photolithography is used to etch the modulation device structure in the heavily doped region 205 . Optionally, when processing the modulation device structure of the heavily doped region 205 in the epitaxial silicon carbide film layer 204, the photolithography method used is at least one of electron beam lithography and deep ultraviolet lithography. The specific processing method is: Dry etching, the etching depth is 200nm-1300nm, and is less than or equal to the thickness of the heavily doped region 205 .

In this embodiment of the present application, by etching the heavily doped region 205, the modulation device structure obtained includes a first preset region 206, a second preset region 207 and a spacer region 208. The spacer region 208 is disposed in the first preset region. Between the area 206 and the second preset area 207. Among them, the first preset area 206 and the second preset area 207 are used to make the electrode area of the modulation device. The spacer region 208 is used to separate the two electrode regions of the modulation device. Optionally, the size of the first preset area 206 is 1 μm-50 μm, the size of the second preset area 207 is 1 μm-50 μm, and the size of the spacing area 208 is 200 nm-1000 nm. After etching the heavily doped region 205 to obtain the first preset region 206, the second preset region 207 and the spacing region 208, the first preset region 206 and the second preset region 207 are doped, Thus, the first electrode region 209 and the second electrode region 210 are obtained to complete the preparation of the modulation device. Specifically, the first preset region 206 is regionally doped according to the first doping type to obtain the first electrode region 209 . The second preset region 207 is regionally doped according to the second doping type to obtain the second electrode region 210 . Wherein, the first doping type is opposite to the second doping type. The first electrode region 209, the second electrode region 210 and the spacer region 208 are activated to obtain an activated modulation device.

In the embodiment of the present application, the first doping type may be N-type doping or P-type doping. Doping the first preset region 206 can be achieved by injecting doping ions, and optionally, the doping ion implantation depth is 10 nm-400 nm. When the first doping type is N-type doping, the first preset region 206 is doped by implanting nitrogen ions or phosphorus ions into the first preset region 206 . When the first doping type is P-type doping, boron ions or aluminum ions are implanted into the first preset region 206 to achieve area doping of the first preset region 206 . The regional doping concentration of the first electrode region 209 obtained after doping the first preset region 206 is 1E17/cm ³ -1E19/cm ³ . The second doping type may be N-type doping or P-type doping, which needs to be determined according to the first doping type. That is, when the first doping type is N-type doping, the second doping type is P-type doping, and when the first doping type is P-type doping, the second doping type is N-type doping. Doping the second preset region 207 can be achieved by injecting doping ions, and optionally, the doping ion implantation depth is 10 nm-400 nm. When the second doping type is N-type doping, the second preset region 207 is doped by implanting nitrogen ions or phosphorus ions into the second preset region 207 . When the second doping type is P-type doping, boron ions or aluminum ions are implanted into the second preset region 207 to achieve area doping of the second preset region 207 . The regional doping concentration of the second electrode region 210 obtained after doping the second preset region 207 is 1E17/cm ³ -1E19/cm ³ .

In the embodiment of the present application, when the doping element and the crystal lattice do not match, the doping ions will form defects in the crystal lattice. Therefore, after obtaining the first electrode region 209 and the second electrode region 210, by assembling the first electrode region 209, the second electrode region 210 and the spacing region 208, the first electrode region 209, the second electrode region 210 and the spacing region 208 can be The spacer region 208 undergoes an activation process to repair defects in the crystal lattice to improve the performance of the material and thereby better exert the role of doping ions. The activation treatment of the first electrode region 209, the second electrode region 210 and the spacer region 208 can be implemented by annealing. Optionally, when annealing the activated doped region, the annealing environment includes but is not limited to vacuum or protective atmosphere, such as N ₂ , Ar, etc. When a protective atmosphere is selected, the pressure can be 0.2-0.5 atmospheres. The annealing temperature is 1500℃-1800℃, the annealing time is 0.5h-5h, and the annealing time is inversely proportional to the annealing temperature. In addition, since silicon carbide will sublime under high temperature conditions, in order to prevent the prepared modulation device structure from being damaged during annealing, a carbon film can be placed on the modulation device structure for protection before annealing. Optional, the thickness of the carbon film is 100nm-1000nm, and the thickness of the carbon film is inversely proportional to the annealing temperature and air pressure.

S109: Prepare a first device protective layer on the second surface.

In the embodiment of the present application, the silicon carbide epitaxial substrate can be removed after completing the preparation of the modulation device structure. Before removing the silicon carbide epitaxial substrate, the prepared modulation device structure needs to be bonded to the support substrate to support the device structure layer. In order to avoid direct contact between the modulation device structure and the support substrate, a first device protection layer 211 may be prepared on the second surface to protect the modulation device structure before bonding the modulation device structure to the support substrate.

In the embodiment of the present application, the modulation device structure includes an opposite first surface and a second surface. The first surface is close to the silicon carbide epitaxial substrate, and is the bottom surface of the modulation device structure. The first surface may be in direct contact with the silicon carbide epitaxial substrate, or may be separated from the silicon carbide epitaxial substrate by a portion of the epitaxial silicon carbide film layer 204 . This is determined by the aforementioned multiple doping processes on the epitaxial silicon carbide thin film layer 204 . If the depth of the impurity ions injected during the doping process is exactly equal to the thickness of the epitaxial silicon carbide film layer 204, the bottom surface of the modulation device structure is directly in contact with the silicon carbide epitaxial base structure. If the depth of the impurity ions injected during the doping process is smaller than the thickness of the epitaxial silicon carbide If the thickness of the thin film layer 204 is small, a portion of the epitaxial silicon carbide thin film layer 204 will be spaced between the bottom surface of the modulation device structure and the silicon carbide epitaxial base structure. The second surface is away from the silicon carbide epitaxial substrate, and the second surface is the top surface of the modulation device structure. The first device protection layer 211 is formed on the top surface of the modulation device structure and the exposed part of the epitaxial silicon carbide film layer 204 surface. The first device protective layer 211 is used to protect the modulation device structure. Optionally, the first device protective layer 211 is made of silicon oxide, silicon nitride, etc. In order to facilitate the bonding of the first device protective layer 211 to the supporting substrate and to facilitate the subsequent removal of the first device protective layer 211 to expose the modulation device structure, the first device protective layer 211 can be made of silicon oxide material.

Optionally, the method of depositing silicon oxide as the first device protective layer 211 on the surface of the modulation device structure includes plasma enhanced chemical vapor deposition (Plasma Enhanced Chemical Vapor Deposition, PECVD), low pressure chemical vapor deposition (Low Pressure Chemical Vapor Deposition). At least one of Vapor Deposition (LPCVD) and Physical Vapor Deposition (PVD). Optionally, the thickness of the first device protection layer 211 is 3 μm-5 μm. In some embodiments, after forming the first device protective layer 211 on the surface of the modulation device structure, the first device protective layer 211 may also be planarized. Optionally, after the planarization process, the surface roughness of the first device protective layer 211 is less than or equal to 0.2 nm.

S111: Obtain the first support substrate, and bond the first support substrate to the first device protective layer to obtain the first bonding structure.

In the embodiment of the present application, after the preparation of the first device protection layer 211 is completed, the first support substrate 212 can be obtained, and then the first support substrate 212 and the first device protection layer 211 are bonded to obtain the first bonding structure. . The first support substrate 212 is used to support the modulation device structure layer to prevent damage to the modulation device structure during the removal of the silicon carbide epitaxial substrate. Since the first support substrate 212 only supports the modulation device structure during the removal of the silicon carbide epitaxial substrate, the first support substrate 212 needs to be removed subsequently to expose the modulation device structure. Therefore, the first support substrate 212 may be a lower cost substrate, such as a silicon substrate. There is usually an oxide layer on the surface of the silicon substrate to protect the silicon substrate. When the silicon substrate is selected as the first support substrate 212, the thickness of the oxide layer on the surface of the silicon substrate should not be too thick to avoid increasing the subsequent removal of the first support. Difficulty of substrate 212. Optionally, when a silicon substrate is selected as the first support substrate 212, the thickness of the oxide layer in the silicon substrate is 500nm-2000nm.

S113: Remove the silicon carbide epitaxial substrate in the first bonding structure and expose the first surface.

In the embodiment of the present application, after the first bonding structure is obtained, the silicon carbide epitaxial substrate in the first bonding structure can be removed. Optionally, the silicon carbide epitaxial substrate can be removed by mechanical grinding. In the case where the first surface is in direct contact with the silicon carbide epitaxial substrate, the first surface can be directly exposed after the silicon carbide epitaxial substrate is removed. In the case where a portion of the epitaxial silicon carbide film layer 204 is spaced between the first surface and the silicon carbide epitaxial substrate, after the silicon carbide epitaxial substrate is removed, it is necessary to continue to epitaxially extend the portion of the space between the first surface and the silicon carbide epitaxial substrate. The silicon carbide film layer 204 is removed, thereby exposing the first surface.

S115: Obtain a second supporting substrate, and bond the second supporting substrate to the first surface to obtain a second bonding structure.

In the embodiment of the present application, after the silicon carbide epitaxial substrate is removed, the first support substrate 212 and the first device protection layer 211 need to be removed to expose the modulation device structure. Before removing the first support substrate 212, it is necessary to obtain the second support substrate 213 and bond the second support substrate 213 to the first surface to obtain a second bonding structure. The second supporting substrate 213 is used to support the modulation device structure and provide a high refractive index contrast for the modulation device structure, so as to achieve localization of the light field in the modulation device structure. Optionally, the second support substrate 213 may be a silicon oxide substrate, a silicon substrate, an aluminum oxide substrate, or the like. When a silicon substrate is selected as the second supporting substrate 213, in order to achieve a good light field localization effect, the thickness of the oxide layer on the surface of the silicon substrate should not be too thin. Alternatively, a silicon substrate is selected as the second supporting substrate 213. At this time, the thickness of the oxide layer in the silicon substrate is 2000nm-5000nm.

S117: Remove the first support substrate in the second bonding structure and the first device protective layer in the second bonding structure to expose the second surface to obtain a modulation device based on silicon carbide.

In the embodiment of the present application, after the second bonding structure is obtained, the first supporting substrate 212 and the first device protective layer 211 are removed to expose the second surface, thereby completing the preparation of the silicon carbide-based modulation device. After the second surface is exposed, metal electrodes may also be prepared in the first electrode region 209 and the second electrode region 210 to lead out the electrodes of the modulation device. In addition, in order to protect the modulator structure, after preparing the metal electrode, a second device protection layer 216 can also be prepared on the top surface of the modulation device to protect the modulation device. Specifically, the first supporting substrate 212 in the second bonding structure and the first device protective layer 211 in the second bonding structure are removed to expose the second surface, thereby obtaining the first device structure. A first metal electrode 214 is prepared in the first electrode region 209 of the first device structure, and a second metal electrode 215 is prepared in the second electrode region 210 of the first device structure, thereby obtaining a second device structure. A second device protective layer 216 is prepared on the second surface of the second device structure to obtain a silicon carbide-based modulation device.

In the embodiment of the present application, when removing the first support substrate 212 and the first device protection layer 211, a corresponding removal process may be selected based on the materials of the first support substrate 212 and the first device protection layer 211. For example, when the first support substrate 212 is a silicon substrate and the first device protective layer 211 is a silicon oxide protective layer, deep silicon etching can be used to remove the silicon layer in the silicon substrate, and then wet etching can be used. The oxide layer and the first device protection layer 211 in the silicon substrate are removed by a method, thereby exposing the top surface of the modulation device structure.

In the embodiment of the present application, after the top surface of the modulation device structure is exposed, the first metal electrode 214 and the second metal electrode 215 can be prepared in the first electrode region 209 and the second electrode region 210 respectively. Optionally, methods of preparing the first metal electrode 214 and the second metal electrode 215 include, but are not limited to, evaporation, electroplating, magnetron sputtering, and the like. Optionally, the first metal electrode 214 and the second metal electrode 215 are made of at least one of gold, silver, copper, aluminum, nickel, and titanium. Optionally, the thickness of the first metal electrode 214 and the second metal electrode 215 is 100 nm-300 nm.

In the embodiment of the present application, the second device protection layer 216 covers the top surface of the modulation device structure and the exposed part of the surface of the epitaxial silicon carbide film layer 204, but does not cover the first metal electrode 214 and the second metal electrode 215. Optionally, the material of the second device protective layer 216 is silicon oxide, silicon nitride, etc., the thickness of the second device protective layer 216 is 500nm-2000nm, and the thickness of the second device protective layer 216 is not less than the thickness of the modulation device structure. . Optionally, the second device protective layer 216 may be prepared by plasma enhanced chemical vapor deposition or physical vapor deposition.

In some embodiments, the first device protection layer 211 may also be used as a protection layer that ultimately protects the modulation device structure. Specifically, when preparing the first device protection layer 211, the thickness of the first device protection layer 211 needs to be no less than the thickness of the modulation device structure. And after removing the first support substrate 212, the first device protective layer 211 is not removed, but electrode holes are etched on the first device protective layer 211, thereby exposing the first electrode region 209 and the second electrode region 210. out, and then prepare the first metal electrode 214 and the second metal electrode 215 in the motor hole. It should be understood that when the first supporting substrate 212 is a silicon substrate, when removing the first supporting substrate 212 , only deep silicon etching can be used to remove the silicon layer in the silicon substrate while retaining the oxide layer. As part of the protective layer of the modulation device structure.

Based on the above introduction to the preparation method of the silicon carbide-based modulation device, the above preparation method will be further described below in conjunction with the structural diagram to facilitate understanding of the structural changes during the preparation process of the silicon carbide-based modulation device. It should be understood that the following drawings are only illustrative illustrations. Based on the above description, those skilled in the art can also obtain other drawings without exerting creative efforts. In addition, the structural changes shown in the following figures are only a feasible example of the preparation method of the silicon carbide-based modulation device, and do not mean that the preparation method of the silicon carbide-based modulation device described in the embodiments of the present application is limited to the following examples. .

Figure 2a is a schematic structural diagram of a high-quality silicon carbide substrate 201 provided by an embodiment of the present application. As shown in Figure 2a, when preparing a modulation device based on silicon carbide, it is first necessary to obtain a high-quality silicon carbide substrate 201. Silicon carbide epitaxial substrate. Figure 2b is a schematic structural diagram of a high-quality silicon carbide substrate 201 after ion implantation provided by an embodiment of the present application. As shown in Figure 2b, after obtaining a high-quality silicon carbide substrate 201, the high-quality silicon carbide substrate is The bottom 201 is ion implanted to form a defect layer 202 in the silicon carbide substrate. Optionally, the implanted ions are H ions and/or He ions, and the implanted surface may be a Si surface or a C surface. The ion implantation energy range is 20keV-2MeV, and the ion implantation dose is 1E15cm ^-2 -1E18cm ^-2 . Figure 2c is a schematic diagram of a structural change for surface treatment of a low-cost silicon carbide substrate 203 provided by an embodiment of the present application. As shown in Figure 2c, the low-cost silicon carbide substrate 203 is obtained as the third support substrate, and the The low-cost silicon carbide substrate 203 is surface-modified to achieve an ultra-flat shape. Figure 2d is a schematic structural diagram of a third bonding structure provided by an embodiment of the present application. As shown in Figure 2d, a third bonding structure can be obtained by bonding a high-quality silicon carbide substrate 201 with a low-cost silicon carbide substrate 203. Bonding structure. Figure 2e is a schematic structural diagram of a silicon carbide epitaxial substrate provided by an embodiment of the present application. As shown in Figure 2e, the third bonding structure is heated to promote the accumulation of implanted ions in the high-quality silicon carbide substrate 201. And micro-defects are formed, and then the micro-defects expand laterally, so that the high-quality silicon carbide substrate 201 in the third bonding structure can be separated along the implanted defect layer 202 to obtain a silicon carbide film bonded on the third support substrate. , and then process the surface of the silicon carbide film to obtain a silicon carbide epitaxial substrate. Then, an epitaxial silicon carbide film layer 204 is epitaxially grown on the surface of the silicon carbide epitaxial substrate. The thickness of the epitaxial silicon carbide film layer 204 is 500nm-1500nm. The doping type is N-type doping, and the doping concentration is 1E ¹³ /cm ³ - 1E ¹⁵ /cm ³ . Figure 2f is a schematic structural diagram of a heavily doped epitaxial silicon carbide thin film layer 204 provided by an embodiment of the present application. As shown in Figure 2f, a preset area in the epitaxial silicon carbide thin film layer 204 is heavily doped. , obtaining the heavily doped region 205. The doping type of the heavily doped region 205 is N-type doping, the doping concentration is 1E15/cm ³ -1E ¹⁷ /cm ³ , the length W of the preset region is 2.2μm-101μm, and the depth h1 of the doped region: 500nm- 1500nm. Figure 2g is a schematic structural diagram after etching the heavily doped region 205 provided by an embodiment of the present application. As shown in Figure 2g, the modulation device structure is obtained by etching the heavily doped region 205. The etching depth is 200nm-1300nm, and is less than or equal to the thickness of the heavily doped region 205 . The modulation device structure includes a first preset area 206, a second preset area 207 and a spacer area 208. Figure 2h is a schematic structural diagram after etching the heavily doped region 205 provided by an embodiment of the present application. As shown in Figure 2h, the first preset region 206 and the second preset region 207 are doped. The doping type of a preset region 206 is N-type doping, the doping concentration is 1E17/cm ³ -1E19/cm ³ , the region length of the first preset region 206 is 1 μm-50 μm, and the doping region depth h2 is 10 nm- 400nm. The doping type of the second preset region 207 is P-type doping, the doping concentration is 1E17/cm ³ -1E19/cm ³ , the region length of the first preset region 206 is 1 μm-50 μm, and the doping region depth h2 is 10 nm. -400nm. The first preset region 206 is regionally doped to obtain the first electrode region 209, the second predetermined region 207 is regionally doped to obtain the second electrode region 210, and then the first electrode region 209 and the second electrode region are 210 and spacer area 208 for activation processing. Figure 2i is a schematic structural diagram after preparing the first device protective layer 211 provided by the embodiment of the present application. As shown in Figure 2i, after the first electrode region 209, the second electrode region 210 and the spacer region 208 are activated , the first device protection layer 211 can be formed on the top surface of the modulation device structure and the surface of the exposed part of the epitaxial silicon carbide film layer 204 to protect the modulation device structure. Figure 2j is a schematic structural diagram of the first device protective layer 211 after planarization according to an embodiment of the present application. As shown in Figure 2j, after the first device protective layer 211 is formed on the surface of the modulation device structure, the first device protective layer 211 is processed by The first device protective layer 211 is planarized so that the surface roughness of the first device protective layer 211 is less than or equal to 0.2 nm. Figure 2k is a schematic structural diagram after bonding the first support substrate 212 provided by the embodiment of the present application. As shown in Figure 2k, after the first device protective layer 211 is prepared, the first support substrate 212 can be obtained, and then The first support substrate 212 and the first device protection layer 211 are bonded to obtain a first bonding structure. The first supporting substrate 212 is a silicon substrate, including a silicon layer and an oxide layer disposed on the silicon layer. Figure 2l is a schematic structural diagram after removing the silicon carbide epitaxial substrate provided by the embodiment of the present application. As shown in Figure 2l, the silicon carbide epitaxial substrate is removed by mechanical grinding, and the bottom surface of the modulation device structure is exposed. Figure 2m is a schematic structural diagram after bonding the second support substrate 213 provided by the embodiment of the present application. As shown in Figure 2m, after the silicon carbide epitaxial substrate is removed, the second support substrate 213 is obtained and The second supporting substrate 213 is bonded to the first surface to obtain a second bonding structure. The second supporting substrate 213 is a silicon substrate, including a silicon layer and an oxide layer disposed on the silicon layer. Figure 2n is a schematic structural diagram after removing the silicon layer in the first support substrate 212 provided by the embodiment of the present application. As shown in Figure 2n, the silicon layer in the silicon substrate is removed by deep silicon etching, thereby The oxide layer in the first support substrate 212 is exposed. Figure 2o is a schematic structural diagram after removing the first support substrate 212 and the first device protective layer 211 according to an embodiment of the present application. As shown in Figure 2o, wet etching can be used to remove the silicon substrate. oxide layer and the first device protection layer 211, thereby exposing the top surface of the modulation device structure. Figure 2p is a schematic structural diagram of a modulation device based on silicon carbide provided by an embodiment of the present application. As shown in Figure 2p, after the top surface of the modulation device structure is exposed, the first electrode region 209 and the first The first metal electrode 214 and the second metal electrode 215 are respectively prepared in the two electrode areas 210, and the second device protection layer 216 is prepared on the top surface of the modulation device structure and the surface of the exposed part of the epitaxial silicon carbide film layer 204, thereby completing the Modulation device preparation of silicon carbide.

The silicon carbide-based modulation device preparation method provided by the embodiment of the present application forms a defect layer 202 at a specific depth of the high-quality silicon carbide substrate 201 by performing ion implantation on the high-quality silicon carbide substrate 201 . A low-cost silicon carbide substrate 203 is provided to realize the bonding of the high-quality silicon carbide substrate 201 and the low-cost silicon carbide substrate 203. Then, high-quality silicon carbide is stripped and post-processed to obtain a silicon carbide epitaxial substrate, and an epitaxial silicon carbide film layer 204 is further epitaxially grown on the silicon carbide epitaxial substrate. Then, the epitaxial silicon carbide film layer 204 is heavily doped in a predetermined area in the epitaxial silicon carbide film layer 204 . Then, the modulation device structure is etched and further doped in the heavily doped region 205 of the epitaxial silicon carbide film layer 204, and a silicon oxide layer is deposited on the surface of the modulation device structure and is planarized. Then the first supporting substrate 212 is provided, secondary wafer bonding is achieved, and the silicon carbide epitaxial substrate in the bonding structure is ground, leaving only the modulation device layer. Then a second support substrate 213 is provided to achieve three wafer bondings. Then, the silicon layer in the first support substrate 212 is removed by deep silicon etching, and the oxide layer of the first support substrate 212 is further removed by wet method and a silicon oxide layer is prepared on the surface of the modulation device structure. Metal electrodes are prepared in the first electrode region 209 and the second electrode region 210 in the modulation device structure, and then a silicon oxide layer covering the top layer is prepared to complete the device structure preparation. Due to its weak electro-optical effect, silicon carbide is difficult to electro-optically modulate the optical path system like lithium niobate. The preparation method described in the embodiments of this application utilizes multiple doping technology and carrier dispersion method to achieve silicon carbide Efficient light modulation in integrated optics. Moreover, through ion beam technology, the silicon carbide film is transferred to the silicon substrate through heterogeneous bonding. On the basis of overcoming the difficulty of preparing silicon carbide materials based on silicon, the cost of a silicon carbide single piece is reduced, and further expansion can be achieved following the progress of the industry. The wafer size is up to 8 inches, while ensuring its compatibility with existing silicon-based integrated circuits.

Embodiments of the present application also provide a silicon carbide-based modulation device, which is prepared by the silicon carbide-based modulation device preparation method as described above. Figure 3 is a schematic structural diagram of a silicon carbide-based modulation device provided by an embodiment of the present application. As shown in Figure 3, the silicon carbide-based modulation device includes: a second support substrate 213 and an epitaxial silicon carbide film layer 204. The second supporting substrate 213 is a silicon substrate, including a silicon layer and an oxide layer disposed on the silicon layer. The epitaxial silicon carbide film layer 204 is disposed on the oxide layer of the second support substrate 213 . A heavily doped region 205 is provided in the epitaxial silicon carbide film layer 204, and a modulation device structure is provided in the heavily doped region 205.

In the embodiment of the present application, the modulation device structure includes a first electrode region 209, a second electrode region 210 and a spacing region 208. The spacing region 208 is disposed between the first electrode region 209 and the second electrode region 210. A first metal electrode 214 is provided in the first electrode area 209 , and a second metal electrode 215 is provided in the second electrode area 210 . A second device protection layer 216 is provided on the modulation device structure, and the first metal electrode 214 and the second metal electrode 215 expose the surface of the second device protection layer 216 .

The silicon carbide-based modulation device provided in the embodiment of the present application is based on the mechanism of carrier dispersion and is applied to silicon carbide photonic devices in a breakthrough manner, solving the modulation problem of silicon carbide in integrated optical systems. By integrating with the silicon substrate, this silicon carbide-based modulation device is easily compatible with the mainstream silicon-based micro-nano product process flow, promoting the development and application of silicon carbide thin film materials in the field of integrated photonic devices.

It should be noted that the above-mentioned order of the embodiments of the present application is only for description and does not represent the advantages and disadvantages of the embodiments. Specific embodiments of this specification have been described above. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recited in the claims can be performed in a different order than in the embodiments and still achieve desired results. Additionally, the processes depicted in the figures do not necessarily require the specific order shown, or sequential order, to achieve desirable results. Multitasking and parallel processing are also possible or may be advantageous in certain implementations.

Each embodiment in this specification is described in a progressive manner. The same and similar parts between the various embodiments can be referred to each other. Each embodiment focuses on its differences from other embodiments. In particular, for the equipment embodiment, since it is basically similar to the method embodiment, the description is relatively simple. For relevant details, please refer to the partial description of the method embodiment.

Those of ordinary skill in the art can understand that all or part of the steps to implement the above embodiments can be completed by hardware, or can be completed by instructing relevant hardware through a program. The program can be stored in a computer-readable storage medium. The above-mentioned The storage media mentioned can be read-only memory, magnetic disks or optical disks, etc.

The above are only preferred embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application shall be included in the protection of the present application. within the range.

Claims (10)

1. A method for preparing a modulation device based on silicon carbide, characterized in that the method includes: Obtain silicon carbide epitaxial substrate; Prepare an epitaxial silicon carbide film layer on the silicon carbide epitaxial substrate (204); Perform heavy doping on the preset area in the epitaxial silicon carbide film layer (204) to obtain a heavily doped area (205); A modulation device structure is prepared in the heavily doped region (205); the modulation device structure includes opposite first and second surfaces, the first surface is close to the silicon carbide epitaxial substrate, and the second surface Stay away from the silicon carbide epitaxial substrate; Prepare a first device protective layer (211) on the second surface; Obtain a first support substrate (212), and bond the first support substrate (212) to the first device protection layer (211) to obtain a first bonding structure; Remove the silicon carbide epitaxial substrate in the first bonding structure and expose the first surface; Obtain a second support substrate (213), and bond the second support substrate (213) to the first surface to obtain a second bonding structure; The first support substrate (212) in the second bonding structure and the first device protection layer (211) in the second bonding structure are removed to expose the second surface, to obtain a carbonization-based Silicon modulation devices. 2. The preparation method according to claim 1, characterized in that said obtaining the silicon carbide epitaxial substrate includes: Obtain silicon carbide substrate; Perform ion implantation on the silicon carbide substrate to form a defect layer in the silicon carbide substrate (202); Obtain a third support substrate, and bond the silicon carbide substrate to the third support substrate to obtain a third bonding structure; The third bonding structure is heat treated to peel off the silicon carbide substrate in the third bonding structure along the defect layer (202) to obtain the carbonized silicon carbide bonded on the third support substrate. Silicon epitaxial substrate. 3. The preparation method according to claim 2, wherein the third supporting substrate is made of silicon carbide or sapphire. 4. The preparation method according to claim 1, characterized in that the epitaxial silicon carbide film layer (204) is a lightly doped epitaxial silicon carbide film layer (204), and the epitaxial silicon carbide film layer (204) The doping concentration is 1E ¹³ /cm ³ -1E ¹⁵ /cm ³ , and the thickness of the epitaxial silicon carbide film layer (204) is 400nm-1500nm. 5. The preparation method according to any one of claims 1 to 4, characterized in that the size of the heavily doped region (205) is 2.2 μm-101 μm, and the thickness of the heavily doped region (205) is less than Equal to the thickness of the epitaxial silicon carbide film layer (204). 6. The preparation method according to claim 5, characterized in that preparing a modulation device structure in the heavily doped region (205) includes: Photolithography is used to etch the modulation device structure in the heavily doped region (205); the etching depth is 200nm-1300nm, and is less than or equal to the thickness of the heavily doped region (205). 7. The preparation method according to claim 5, characterized in that the modulation device structure includes a first preset area (206), a second preset area (207) and a spacing area (208), and the spacing area (208) 208) Set between the first preset area (206) and the second preset area (207); prepare a first device protection layer (211) on the second surface; Previously, the method also included: Perform regional doping on the first preset region (206) according to the first doping type to obtain a first electrode region (209); The second preset region (207) is regionally doped according to a second doping type to obtain a second electrode region (210); wherein the first doping type is opposite to the second doping type; Perform activation processing on the first electrode area (209), the second electrode area (210) and the spacing area (208) to obtain an activated modulation device. 8. The preparation method according to claim 7, characterized in that the size of the first preset area (206) is 1 μm-50 μm, and the size of the second preset area (207) is 1 μm-50 μm, so The size of the spacer region (208) is 200nm-1000nm. 9. The preparation method according to claim 8, characterized in that: combining the first support substrate (212) in the second bonding structure and the first device protection layer in the second bonding structure (211) is removed to expose the second surface to obtain a modulation device based on silicon carbide, including: The first supporting substrate (212) in the second bonding structure and the first device protection layer (211) in the second bonding structure are removed to expose the second surface to obtain the first device structure; A first metal electrode (214) is prepared in the first electrode region (209) of the first device structure, and a second metal electrode (215) is prepared in the second electrode region (210) of the first device structure. , obtain the second device structure; A second device protective layer (216) is prepared on the second surface in the second device structure to obtain a modulation device based on silicon carbide. 10. A silicon carbide-based modulation device, characterized in that the modulation device is prepared by the silicon carbide-based modulation device preparation method according to any one of claims 1-9; The modulation device includes: a second support substrate (213) and an epitaxial silicon carbide film layer (204); The epitaxial silicon carbide film layer (204) is provided on the second support substrate (213); The epitaxial silicon carbide film layer (204) is provided with a heavily doped region (205); A modulation device structure is provided in the heavily doped region (205).