A β-Ga2O3 epitaxial structure and its manufacturing method, and semiconductor devices

Abstract

This application provides a β-Ga2O3 epitaxial structure, its manufacturing method, and a semiconductor device. The method includes: providing a substrate; forming a Ga molecule nucleation layer on the substrate; and forming a β-Ga2O3 epitaxial layer on the Ga molecule nucleation layer. In this application, a Ga molecule nucleation layer is first formed on the substrate, followed by the formation of the β-Ga2O3 epitaxial layer. The Ga molecule nucleation centers in the Ga molecule nucleation layer can lower the thermodynamic barrier and improve the growth kinetics of the β-Ga2O3 epitaxial layer, promoting the adsorption and reaction of Ga atoms and promoting the lateral diffusion of Ga atoms. This improves the crystal quality and growth rate of the β-Ga2O3 epitaxial layer and reduces its surface roughness.

Description

Technical Field

[0001] This application relates to the field of semiconductor technology, and more specifically to a β-Ga2O3 epitaxial structure, its manufacturing method, and semiconductor devices. Background Technology

[0002] β-Ga₂O₃ has attracted significant attention in ultra-high voltage and high power device applications due to its superior material properties, including an ultra-wide bandgap, high breakdown field strength, and high Baliga figure of merit. The application of β-Ga₂O₃ can significantly reduce power loss and improve energy conversion efficiency. Furthermore, β-Ga₂O₃ single crystals can be grown using a melt-grown method, enabling high-quality, large-size, and low-cost homoepitaxial growth. The superior cost advantage of β-Ga₂O₃ makes it a potential replacement for silicon carbide and gallium nitride in low- and medium-voltage applications; in ultra-high voltage applications, it demonstrates high breakdown voltage and high power density. β-Ga₂O₃ epitaxial films are generally used as channel layers in semiconductor devices. To improve device performance, high crystal quality and low surface roughness are required for β-Ga₂O₃ epitaxial films.

[0003] Epitaxial techniques for β-Ga2O3 thin films mainly include Metal-organic Chemical Vapor Deposition (MOCVD), Molecular Beam Epitaxy (MBE), and Halide Vapor Phase Epitaxy (HVPE). Among these, MOCVD is best suited for large-scale growth and offers more precise control over the growth rate and doping level, making it the primary epitaxial process.

[0004] However, as Figure 1 As shown, the β-Ga2O3 thin film grown by MOCVD in related technologies has obvious island-like structures on its surface, which are uneven and lead to increased surface roughness. At the same time, the β-Ga2O3 thin film grown by MOCVD in related technologies also suffers from poor crystal quality, which limits the performance of semiconductor devices.

[0005] Therefore, improvements are needed to at least partially address the aforementioned problems. Summary of the Invention

[0006] The summary section introduces a series of simplified concepts, which will be further explained in detail in the detailed description section. This summary section is not intended to limit the key and essential technical features of the claimed technical solution, nor is it intended to determine the scope of protection of the claimed technical solution.

[0007] To at least partially solve the above-mentioned technical problems, this application provides a method for manufacturing a β-Ga2O3 epitaxial structure, comprising:

[0008] Provide substrate;

[0009] A Ga molecule nucleation layer is formed on the substrate;

[0010] A β-Ga2O3 epitaxial layer is formed on the Ga molecule nucleation layer.

[0011] For example, during the formation of the β-Ga2O3 epitaxial layer, Ga molecules in the Ga molecule nucleation layer are split into Ga atoms and then oxidized to β-Ga2O3, so that the Ga molecule nucleation layer becomes part of the β-Ga2O3 epitaxial layer.

[0012] For example, the Ga molecule nucleation layer is grown in an MOCVD reaction chamber, with nitrogen as the carrier gas, a growth temperature of 500℃-700℃, a Ga source of TMGa or TEGa, and a Ga source flow rate of 80sccm-200sccm.

[0013] For example, when the Ga source is TMGa, the Ga molecules in the Ga molecule nucleation layer include at least one of Ga(CH3)2 and Ga(CH3);

[0014] When the Ga source is TEGa, the Ga molecules in the Ga molecule nucleation layer include at least one of Ga(C2H5)2 and Ga(C2H5).

[0015] Exemplarily, the growth of the Ga molecule nucleation layer in an MOCVD reaction chamber includes:

[0016] The Ga source pipeline is alternately turned on and off in a cyclic manner. Each cycle includes one turn-on operation and one turn-off operation. In each cycle, the turn-on duration of the Ga source pipeline is the first duration, and the turn-off duration of the Ga source pipeline is the second duration.

[0017] The Ga source pipeline is turned on for the duration of the first duration.

[0018] For example, the first duration is 1 min to 3 min, and the second duration is 0.5 min to 1 min.

[0019] For example, the number of cycles is greater than or equal to 1 and less than or equal to 5.

[0020] For example, before forming the Ga molecule nucleation layer on the substrate, a pretreatment step is further included, the pretreatment comprising: treating the substrate in an oxygen atmosphere at 600°C-1000°C for 5 min-20 min.

[0021] In another aspect, this application provides a β-Ga2O3 epitaxial structure, which is obtained by the aforementioned method.

[0022] In another aspect, this application provides a semiconductor device comprising the aforementioned β-Ga2O3 epitaxial structure.

[0023] The β-Ga2O3 epitaxial structure, its manufacturing method, and semiconductor device disclosed in this application first form a Ga molecule nucleation layer on a substrate, and then form a β-Ga2O3 epitaxial layer. The Ga molecule nucleation centers in the Ga molecule nucleation layer can reduce the thermodynamic barrier to the growth of the β-Ga2O3 epitaxial layer and improve the growth kinetics, promote the adsorption and reaction of Ga atoms, and promote the lateral diffusion of Ga atoms, thereby improving the crystal quality and growth rate of the β-Ga2O3 epitaxial layer and reducing the surface roughness of the β-Ga2O3 epitaxial layer. Attached Figure Description

[0024] The following drawings, which are incorporated herein by reference and are used to understand this application, illustrate embodiments of the invention and their descriptions to explain the principles of the invention.

[0025] In the attached image:

[0026] Figure 1 The surface morphology of the β-Ga2O3 epitaxial layer in the related technology is shown;

[0027] Figures 2A-2D This illustration shows a cross-sectional schematic diagram of the β-Ga2O3 epitaxial structure obtained by sequentially implementing a method for manufacturing a β-Ga2O3 epitaxial structure according to an exemplary embodiment of this application;

[0028] Figure 3 A flowchart illustrating a method for manufacturing a β-Ga2O3 epitaxial structure according to an exemplary embodiment of this application is shown;

[0029] Figure 4 This image shows a morphological diagram of the surface of a β-Ga2O3 epitaxial layer according to an exemplary embodiment of this application. Detailed Implementation

[0030] The present application will now be described more fully with reference to the accompanying drawings, in which embodiments of the present application are illustrated. However, the present application can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. Rather, providing these embodiments will make the disclosure thorough and complete, and will fully convey the scope of the present application to those skilled in the art. In the drawings, for clarity, the dimensions and relative dimensions of layers and regions may be exaggerated. The same reference numerals denote the same elements throughout.

[0031] 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, components, areas, layers, and / or portions, these elements, components, areas, layers, and / or portions should not be limited by these terms. These terms are only used to distinguish one element, component, area, layer, or portion from another element, component, area, layer, or portion. Therefore, without departing from the teachings of this application, the first element, component, area, layer, or portion discussed below may be referred to as the second element, component, area, layer, or portion.

[0032] Spatial relation terms such as “below,” “under,” “below,” “under,” “above,” “above,” etc., are used herein for convenience of description 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 are intended to also include different orientations of the device in use and operation. For example, if the device in the figure is flipped, then the element or feature described as “below” or “under” the other element or feature will be oriented “above” the other element or feature. Therefore, the exemplary terms “below” and “under” can include both upper and lower orientations. The device may be otherwise oriented (rotated 90 degrees or otherwise) and the spatial descriptive terms used herein will be interpreted accordingly.

[0033] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of this application. When used herein, the singular forms “a,” “an,” and “the” are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the terms “comprise” and / or “comprising,” when used in this specification, identify the presence of the stated features, integers, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups. When used herein, the term “and / or” includes any and all combinations of the associated listed items.

[0034] Embodiments of the application are described herein with reference to cross-sectional views illustrating ideal embodiments (and intermediate structures). Thus, variations from the shapes shown can be anticipated due to, for example, manufacturing techniques and / or tolerances. Therefore, embodiments of the application should not be limited to the specific shapes of the regions shown herein, but include shape deviations due to, for example, manufacturing processes. For example, implantation regions shown as rectangular typically have rounded or curved features at their edges and / or implantation concentration gradients, rather than a binary change from implantation regions to non-implantation regions. Similarly, buried regions formed by implantation can result in some implantation in the region between the buried region and the surface traversed during implantation. Therefore, the regions shown in the figures are substantially schematic, and their shapes are not intended to show the actual shapes of the regions of the device and are not intended to limit the scope of the application.

[0035] Unless otherwise defined, all terms used herein (including technical and scientific terms) shall have the same meaning as commonly understood by one of ordinary skill in the art. It will also be understood that terms as defined in commonly used dictionaries shall be construed as having a meaning consistent with their meaning in the relevant field and / or the context of this specification, and not as interpreted in an ideal or overly formal sense, unless expressly defined herein.

[0036] To fully understand this application, a detailed structure will be presented in the following description to illustrate the technical solutions proposed in this application. Preferred embodiments of this application are described in detail below; however, in addition to these detailed descriptions, this application may have other implementation methods.

[0037] In related technologies, the diffusion and migration ability of Ga atoms on the material surface is generally enhanced by adjusting the growth conditions such as O / Ga ratio, temperature, and pressure during the growth process of β-Ga2O3 epitaxial films, thereby suppressing the two-site island growth of the film, so as to improve the crystal quality of β-Ga2O3 epitaxial films and reduce the surface roughness of β-Ga2O3 epitaxial films.

[0038] However, methods to improve crystal quality and reduce surface roughness by adjusting growth conditions require exploring the optimal experimental window under each condition. The adjustment process is complex, costly, and inefficient. At the same time, the adjustable range of growth conditions is limited, and the effect on improving crystal quality is not obvious.

[0039] Therefore, in view of the aforementioned technical problems, this application proposes a method for manufacturing a β-Ga2O3 epitaxial structure, comprising:

[0040] Provide substrate;

[0041] A Ga molecule nucleation layer is formed on the substrate;

[0042] A β-Ga2O3 epitaxial layer is formed on the Ga molecule nucleation layer.

[0043] The method for manufacturing the β-Ga2O3 epitaxial structure disclosed in this application involves first forming a Ga molecule nucleation layer on a substrate, and then forming a β-Ga2O3 epitaxial layer. The Ga molecule nucleation centers in the Ga molecule nucleation layer can reduce the thermodynamic barrier to the growth of the β-Ga2O3 epitaxial layer and improve the growth kinetics, thereby promoting the adsorption and reaction of Ga atoms and promoting the lateral diffusion of Ga atoms. This improves the crystal quality and growth rate of the β-Ga2O3 epitaxial layer and reduces the surface roughness of the β-Ga2O3 epitaxial layer.

[0044] Example 1

[0045] The following reference Figures 2A-2D , Figure 3 as well as Figure 4 This application describes a method for manufacturing a β-Ga2O3 epitaxial structure, wherein... Figures 2A-2D This illustration shows a cross-sectional schematic diagram of the β-Ga2O3 epitaxial structure obtained by sequentially implementing a method for manufacturing a β-Ga2O3 epitaxial structure according to an exemplary embodiment of this application. Figure 3 A flowchart illustrating a method for manufacturing a β-Ga2O3 epitaxial structure according to an exemplary embodiment of this application is shown. Figure 4 This image shows a morphological diagram of the surface of a β-Ga2O3 epitaxial layer according to an exemplary embodiment of this application.

[0046] First, execute step S1, as follows: Figure 2A As shown, a substrate 200 is provided.

[0047] In one example, the substrate 200 may be a Ga2O3 substrate or an Al2O3 substrate, or it may be other heterogeneous substrates, which are not limited in this application.

[0048] Next, proceed to step S2, as follows: Figure 2B As shown, a Ga molecule nucleation layer 210 is formed on a substrate 200.

[0049] In one example, a Ga molecular nucleation layer 210 is grown in an MOCVD reaction chamber. Nitrogen is used as the carrier gas, and the growth temperature (i.e., the temperature of the MOCVD reaction chamber) is 500℃-700℃, for example, 500℃, 550℃, 600℃, 650℃, or 700℃. The Ga source is trimethylgallium (TMGa) or triethylgallium (TEGa), and the Ga source flow rate is 80 sccm-200 sccm, for example, 80 sccm, 100 sccm, 130 sccm, 150 sccm, 180 sccm, or 200 sccm. The carrier gas carries the Ga source into the reaction chamber via a Ga source bottle.

[0050] In one example, when the Ga source is TMGa, the Ga molecules in the Ga molecule nucleation layer 210 include at least one of Ga(CH3)2 and Ga(CH3). Specifically, TMGa cleaves to form Ga(CH3)2 and methyl groups, wherein some or all of the Ga(CH3)2 may further cleave to form Ga(CH3) and methyl groups.

[0051] In one example, when the Ga source is TEGa, the Ga molecules in the Ga molecule nucleation layer 210 include at least one of Ga(C2H5)2 and Ga(C2H5). Specifically, TEGa cleaves to form Ga(C2H5)2 and ethyl groups, wherein some or all of the Ga(CH3)2 may further cleave to form Ga(C2H5) and ethyl groups.

[0052] In one example, before forming the Ga molecular nucleation layer 210 on the substrate 200, a pretreatment step is included. The pretreatment includes treating the substrate in an oxygen atmosphere at 600°C-1000°C for 5-20 minutes. The oxygen atmosphere refers to an environment containing oxygen, and may also include nitrogen. Exemplarily, by pretreating the substrate 200, volatile contaminants on the surface of the substrate 200 can be removed, and stress damage caused during substrate 200 processing can be repaired, thereby facilitating the epitaxial growth of the Ga molecular nucleation layer 210 and the β-Ga2O3 epitaxial layer 220.

[0053] Next, proceed to step S3, as follows: Figure 2C As shown, a β-Ga2O3 epitaxial layer 220 is formed on the Ga molecule nucleation layer 210.

[0054] In one example, a β-Ga2O3 epitaxial layer 220 is grown in an MOCVD reaction chamber using nitrogen as the carrier gas. The growth temperature (i.e., the temperature of the MOCVD reaction chamber) is 700℃-1000℃, for example, 700℃, 750℃, 800℃, 850℃, 900℃, 950℃, or 1000℃. The growth pressure (i.e., the pressure of the MOCVD reaction chamber) is 30mbar-80mbar, for example, 30mbar, 40mbar, or 50mbar. The source of Ga is TMGa or TEGa, with a flow rate of 100 sccm-500 sccm. For example, the flow rate of the Ga source can be 100 sccm, 200 sccm, 300 sccm, 400 sccm, or 500 sccm. The source of O is oxygen, and the O / Ga ratio (molar ratio of group VI source to group III source) is 200-500. For example, the O / Ga ratio can be 200, 300, 400, or 500. For example, taking TMGa as the source of Ga, during the growth of the β-Ga2O3 epitaxial layer 220, TMGa gradually decomposes to form Ga atoms. The Ga atoms react with oxygen to grow β-Ga2O3. The gradual decomposition of TMGa to form Ga atoms includes: TMGa first decomposes to form Ga(CH3)2 and methyl groups, Ga(CH3)2 further decomposes to form Ga(CH3) and methyl groups, and Ga(CH3) further decomposes to form Ga atoms and methyl groups. For example, taking TEGa as the Ga source, TEGa gradually cleaves to form Ga atoms, including: TEGa first cleaves to form Ga(C2H5)2 and ethyl groups, Ga(C2H5)2 further cleaves to form Ga(C2H5) and ethyl groups, and Ga(C2H5) further cleaves to form Ga atoms and ethyl groups. For example, during the growth of the β-Ga2O3 epitaxial layer 220, the methyl or ethyl groups formed by cleavage react with oxygen to form byproducts such as water, carbon dioxide, and carbon monoxide, which are then discharged with the carrier gas.

[0055] In one example, during the formation of the β-Ga2O3 epitaxial layer, the Ga molecule nucleation layer 210 can play a wetting role in the chemical reaction. Specifically, Ga molecules in the Ga molecule nucleation layer 210 will aggregate to form Ga molecule nucleation centers. During the growth of the β-Ga2O3 epitaxial layer 220, the Ga molecule nucleation centers can provide chemical sites, reduce the thermodynamic barrier during the growth of the β-Ga2O3 epitaxial layer 220 and improve the growth kinetics, promote the adsorption and reaction of Ga atoms, and thus improve the growth rate of the β-Ga2O3 epitaxial layer 220.

[0056] Simultaneously, during the growth of the β-Ga2O3 epitaxial layer 220, the Ga molecule nucleation centers attract Ga atoms to continuously aggregate around them and diffuse laterally. In other words, the Ga molecule nucleation centers promote the lateral diffusion of Ga atoms, and the lateral growth of Ga atoms around the nucleation centers enhances the lateral epitaxy. At the same time, lateral growth competes with the longitudinal growth of the two-dimensional islands. When lateral growth is promoted, more Ga atoms participate in lateral growth, thereby inhibiting longitudinal growth and resulting in a more robust β-Ga2O3 epitaxial layer. The growth mode of β-Ga₂O₃ epitaxial layer 220 gradually transitions to a step-flow mode. In the step-flow mode, the β-Ga₂O₃ epitaxial layer 220 grows layer by layer along a step-like structure. This growth mode enables the β-Ga₂O₃ epitaxial layer 220 to grow in a more ordered and uniform manner. This order and uniformity avoids defects such as dislocations and twins caused by faster vertical stacking, thus reducing the generation of crystal defects and improving the crystal quality of the β-Ga₂O₃ epitaxial layer 220. Furthermore, because it grows layer by layer, rather than forming an uneven island structure, such as… Figure 4 As shown, it can form a uniform and flat film surface, which can effectively reduce the surface roughness of the β-Ga2O3 epitaxial layer 220.

[0057] In one example, the growth of a Ga molecule nucleation layer 210 in an MOCVD reaction chamber includes: cyclically turning the Ga source pipeline (the Ga source pipeline is a pipeline that introduces a Ga source into the reaction chamber) on and off alternately. Each cycle includes one on operation and one off operation performed sequentially. In each cycle, the on duration of the Ga source pipeline is a first duration, and the off duration of the Ga source pipeline is a second duration; the Ga source pipeline is then turned on for the first duration. By cyclically and alternately turning the Ga source pipeline on and off during the growth of the Ga molecule nucleation layer 210, the cyclic pulse growth of the Ga molecule nucleation layer 210 can be achieved. This can prevent the excessive growth of Ga molecule nucleation centers and the formation of agglomeration, thereby making the distribution of Ga molecule nucleation centers more uniform. This can further reduce the thermodynamic barrier of β-Ga2O3 epitaxial layer growth and improve growth kinetics, promote the adsorption and reaction of Ga atoms, and further promote the lateral diffusion of Ga atoms. This can further improve the crystal quality and growth rate of β-Ga2O3 epitaxial layer and reduce the surface roughness of β-Ga2O3 epitaxial layer.

[0058] In one example, the first duration is 1-3 minutes, for example, the first duration can be 1 minute, 1.5 minutes, 2 minutes, 2.5 minutes, or 3 minutes, or any other suitable range; the first duration is 0.5 minutes-1 minute, for example, the first duration can be 0.5 minutes, 0.6 minutes, 0.7 minutes, 0.8 minutes, 0.9 minutes, or 1 minute, or any other suitable range. The on and off durations of the Ga source pipeline should be set reasonably according to actual needs.

[0059] In one example, the number of cycles of turning the Ga source pipeline on and off is greater than or equal to 1 and less than or equal to 5, so as to control the thickness of the Ga nucleation layer 210 within a certain range and avoid the longitudinal growth rate of the β-Ga2O3 epitaxial layer being too fast due to the Ga nucleation layer 210 being too thick.

[0060] In one example, such as Figure 2D As shown, during the formation of the β-Ga2O3 epitaxial layer 220, Ga molecules in the Ga molecule nucleation layer 210 are fragmented into Ga atoms and subsequently oxidized to β-Ga2O3, thus transforming the Ga molecule nucleation layer 210 into a partial β-Ga2O3 epitaxial layer 220. The process of Ga molecule fragmentation into Ga atoms can be referred to above and will not be repeated here. Exemplarily, the Ga molecule nucleation layer 210 disappears after the epitaxial growth process is completed. The transformation of the Ga molecule nucleation layer 210 into a partial β-Ga2O3 epitaxial layer 220 can further improve the growth rate of the β-Ga2O3 epitaxial layer 220.

[0061] In one example, after growing a β-Ga2O3 epitaxial layer 220 in the MOCVD reaction chamber, the temperature of the reaction chamber was lowered to below 150°C in an oxygen atmosphere to end the entire epitaxial growth process.

[0062] This concludes the description of the key steps in the method for manufacturing the β-Ga2O3 epitaxial structure of this application. It is worth mentioning that the above method for manufacturing the β-Ga2O3 epitaxial structure is only illustrative. The preparation of a complete β-Ga2O3 epitaxial structure may include other steps, which will not be elaborated here.

[0063] In summary, the method for manufacturing the β-Ga2O3 epitaxial structure of this application first forms a Ga molecule nucleation layer on a substrate, and then forms a β-Ga2O3 epitaxial layer. The Ga molecule nucleation centers in the Ga molecule nucleation layer can reduce the thermodynamic barrier and improve the growth kinetics of the β-Ga2O3 epitaxial layer, promote the adsorption and reaction of Ga atoms, and promote the lateral diffusion of Ga atoms, thereby improving the crystal quality and growth rate of the β-Ga2O3 epitaxial layer and reducing its surface roughness. For example, during the formation of the β-Ga2O3 epitaxial layer, the Ga source pipeline is alternately turned on and off in a cyclic manner, which can make the distribution of Ga molecule nucleation centers more uniform, further improving the crystal quality and growth rate of the β-Ga2O3 epitaxial layer and reducing its surface roughness.

[0064] Example 2

[0065] Another embodiment of this application provides a β-Ga2O3 epitaxial structure, which is manufactured using the manufacturing method of the β-Ga2O3 epitaxial structure described in Embodiment 1.

[0066] In summary, the β-Ga₂O₃ epitaxial structure of this application, fabricated using the aforementioned method, involves first forming a Ga molecule nucleation layer on a substrate, followed by the formation of the β-Ga₂O₃ epitaxial layer. The Ga molecule nucleation centers in the Ga molecule nucleation layer lower the thermodynamic barrier to the growth of the β-Ga₂O₃ epitaxial layer and improve its growth kinetics, promoting the adsorption and reaction of Ga atoms and lateral diffusion of Ga atoms. This, in turn, improves the crystal quality and growth rate of the β-Ga₂O₃ epitaxial layer and reduces its surface roughness. For example, during the formation of the β-Ga₂O₃ epitaxial layer, cyclically switching the Ga source pipeline on and off allows for a more uniform distribution of Ga molecule nucleation centers, further improving the crystal quality and growth rate of the β-Ga₂O₃ epitaxial layer and reducing its surface roughness.

[0067] Example 3

[0068] In another embodiment of this application, a semiconductor device is provided, which includes the β-Ga2O3 epitaxial structure described in Embodiment 2. The semiconductor device can be a power semiconductor device.

[0069] Although several embodiments have been described herein, it should be understood that many other modifications and embodiments will arise in the mind of those skilled in the art, all of which will fall within the spirit and scope of the concept disclosed herein. More specifically, various modifications and changes may be made in terms of the arrangement and / or components of the subject matter within the scope of this disclosure, the drawings, and the appended claims. In addition to modifications and changes in the components and / or arrangement, the use of alternative methods will also be obvious to those skilled in the art.

Claims

1. A method for manufacturing a β-Ga2O3 epitaxial structure, characterized by, include: Provide substrate; A Ga molecule nucleation layer is formed on the substrate; A β-Ga2O3 epitaxial layer is formed on the Ga molecule nucleation layer.

2. The manufacturing method according to claim 1, characterized in that, During the formation of the β-Ga2O3 epitaxial layer, Ga molecules in the Ga molecule nucleation layer are split into Ga atoms and then oxidized to β-Ga2O3, so that the Ga molecule nucleation layer becomes part of the β-Ga2O3 epitaxial layer.

3. The manufacturing method according to claim 1, characterized in that, The Ga molecule nucleation layer is grown in an MOCVD reaction chamber with nitrogen as the carrier gas, at a growth temperature of 500℃-700℃, and the Ga source is either TMGa or TEGa with a flow rate of 80 sccm-200 sccm.

4. The manufacturing method according to claim 3, characterized in that, When the Ga source is TMGa, the Ga molecules in the Ga molecule nucleation layer include at least one of Ga(CH3)2 and Ga(CH3); When the Ga source is TEGa, the Ga molecules in the Ga molecule nucleation layer include at least one of Ga(C2H5)2 and Ga(C2H5).

5. The manufacturing method according to claim 3, characterized in that, The Ga molecule nucleation layer is grown in an MOCVD reaction chamber, comprising: The Ga source pipeline is alternately turned on and off in a cyclic manner. Each cycle includes one turn-on operation and one turn-off operation. In each cycle, the turn-on duration of the Ga source pipeline is the first duration, and the turn-off duration of the Ga source pipeline is the second duration. The Ga source pipeline is turned on for the duration of the first duration.

6. The manufacturing method according to claim 5, characterized in that, The first duration is 1 min to 3 min, and the second duration is 0.5 min to 1 min.

7. The manufacturing method according to claim 5, characterized in that, The number of cycles is greater than or equal to 1 and less than or equal to 5.

8. The manufacturing method according to claim 1, characterized in that, Before forming the Ga molecule nucleation layer on the substrate, the method further includes a pretreatment step of the substrate, which includes treating the substrate in an oxygen atmosphere at 600°C-1000°C for 5 min-20 min.

9. A β-Ga₂O₃ epitaxial structure, characterized in that, The β-Ga2O3 epitaxial structure is obtained by the method described in any one of claims 1-8.

10. A semiconductor device, characterized in that, The semiconductor device includes the β-Ga2O3 epitaxial structure as described in claim 9.

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