Silicon carbide MOS (Metal Oxide Semiconductor) tube structure and manufacturing method of silicon carbide MOS tube structure
By setting reinforcement and buffer layers in the silicon carbide MOSFET structure and optimizing the electric field distribution, the reliability problem of the silicon carbide MOSFET structure is solved, and higher stability and current transmission efficiency are achieved.
Patent Information
- Application Number
- CN202410396874.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-04-02
- Publication Date
- 2025-10-17
AI Technical Summary
The reliability of existing silicon carbide MOSFET structures needs to be improved, especially since the oxide layer is easily broken down under high electric field conditions.
By setting reinforcement and buffer layers in the silicon carbide MOS transistor structure, the electric field distribution is optimized, the electric field uniformity is ensured, and the impact of electric field intensity non-uniformity on the structure is reduced.
This improves the reliability and stability of silicon carbide MOSFETs, reduces the risk of oxide layer breakdown, and enhances structural consistency and current transmission efficiency.
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Figure CN120812968A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of semiconductor technology, and in particular to a silicon carbide MOS tube structure and a manufacturing method of a silicon carbide MOS tube. BACKGROUND
[0002] A MOS structure (Metal-Oxide-Semiconductor) is an electronic device structure based on semiconductor materials, which is composed of metal electrodes, oxide layers, and semiconductors. The MOS structure has a wide range of application scenarios, including but not limited to the following fields: integrated circuits, such as logic gates, memories, and amplifiers; high-frequency electronic devices; communication fields, such as radio frequency amplifiers, signal mixers, and other high-frequency electronic devices; power management, such as DC-DC converters, power inverters, and the like. The characteristics of the MOS structure include high input impedance, low power consumption, large dynamic range, and strong integrability. In MOS structure devices, the breakdown field of a silicon carbide MOS structure can be several times that of a silicon MOS structure, so a high withstand voltage can be achieved with low impedance and thin thickness. Even so, the continuous improvement of the reliability of silicon carbide MOS devices is still an important research and technical development direction for those skilled in the art. SUMMARY
[0003] To solve the technical problem of how to improve the reliability of a silicon carbide MOS tube structure, the present application provides a silicon carbide MOS tube structure and a manufacturing method of a silicon carbide MOS tube structure. The silicon carbide MOS tube structure achieves the technical effect of enhancing the reliability of the silicon carbide MOS tube structure by means of setting a reinforcing layer.
[0004] In one aspect, the present application provides a method for manufacturing a silicon carbide MOS tube structure, which includes: generating an epitaxial layer having a first surface and a second surface; generating a first body region, a second body region and a reinforcing layer on the epitaxial layer, the first body region and the second body region are located on a side of the epitaxial layer close to the second surface, the first body region and the second body region are oppositely and spacedly arranged in a first direction, the first body region and the second body region extend along a second direction intersecting the first direction, the reinforcing layer is located between the first body region and the second body region, the reinforcing layer extends along the first direction, and the reinforcing layer is in contact with the first body region, the second body region and the epitaxial layer; forming a first source region on the first body region and a second source region on the second body region, the first source region is located at one end of the first body region close to the second surface, the second source region is located at one end of the second body region close to the second surface, and the first source region and the second source region extend along the second direction; forming an oxide layer on the second surface, the oxide layer extends along the second direction, and the oxide layer connects the epitaxial layer, the first body region, the second body region, the first source region, the second source region and the reinforcing layer; wherein the first body region, the second body region and the reinforcing layer have the same doping concentration; the first body region, the second body region and the reinforcing layer have a first doping type, and the first source region, the second source region and the epitaxial layer have a second doping type.
[0005] In one embodiment of the present application, the step of generating the first body region, the second body region and the reinforcing layer on the epitaxial layer specifically includes: forming a plurality of reinforcing layers between the first body region and the second body region, and the plurality of reinforcing layers are arranged and spaced in the second direction.
[0006] In one embodiment of the present application, the method further includes: generating a buffer layer in the epitaxial layer, the buffer layer is arranged between two adjacent reinforcing layers, the buffer layer has the second doping type, and the buffer layer has a doping concentration different from that of the epitaxial layer.
[0007] In one embodiment of the present application, the doping concentration of the buffer layer is lower than that of the first source region and the second source region, and the doping concentration of the epitaxial layer is lower than that of the buffer layer.
[0008] In one embodiment of the present application, the distance between two adjacent reinforcing layers ranges from 0.1 to 10 microns.
[0009] In one embodiment of the present application, the number of impurity atoms per cubic centimeter of the buffer layer ranges from 10 17 to 10 18 .
[0010] In one embodiment of the present application, the thickness of the buffer layer in the direction from the first surface to the second surface is less than the thickness of the reinforcing layer in the direction from the first surface to the second surface.
[0011] In one embodiment of the present application, the distance of the buffer layer in the direction from the first surface to the second surface ranges from 0.1 to 10 microns.
[0012] In another aspect, the present application provides a silicon carbide MOS transistor structure prepared by the method for manufacturing a silicon carbide MOS transistor structure according to any one of the above embodiments.
[0013] In still another aspect, the present application provides a silicon carbide MOS transistor structure, which includes, for example: an epitaxial layer having opposite first and second surfaces; first and second body regions disposed in the epitaxial layer, the first and second body regions being located on a side close to the second surface, the first and second body regions being oppositely and spacedly disposed in a first direction, the first and second body regions extending in a second direction intersecting the first direction; a reinforcing layer located between the first and second body regions, the reinforcing layer extending in the first direction, the reinforcing layer being in contact with the first and second body regions and the epitaxial layer; first and second source regions, the first source region being embedded in the first body region, the second source region being embedded in the second body region, the first source region being located at an end of the first body region close to the second surface, the second source region being located at an end of the second body region close to the second surface, the first and second source regions extending in the second direction; an oxide layer located on the second surface and extending in the second direction, the oxide layer connecting the epitaxial layer, the first and second body regions, the first and second source regions, and the reinforcing layer; the first and second body regions having the same doping concentration as the reinforcing layer; the first and second body regions and the reinforcing layer being of P-type, the first and second source regions and the epitaxial layer being of N-type.
[0014] As can be seen from the above, the technical solution has at least one or more of the following beneficial effects:
[0015] In an embodiment of the present invention, a reinforcement layer is provided, and the reinforcement layer is located between the first body region and the second body region. By providing the reinforcement layer, a partial conductive area of the epitaxial layer between the first body region and the second body region is reinforced, while the channel width is not affected. The electric field distribution is increased, making the electric field more uniform, and the electric field strength near the channel surface is reduced, thereby reducing the impact of uneven electric field strength on the silicon carbide MOS tube structure and reducing the risk of oxide layer breakdown, thereby improving the reliability of the silicon carbide MOS tube structure. Moreover, since the first body region, the second body region and the reinforcement layer have the same doping concentration and the same doping type, it helps to ensure the consistency and stability of the structure, improve the reliability, and thus enhance the stability of the silicon carbide MOS tube structure. BRIEF DESCRIPTION OF THE DRAWINGS
[0016] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.
[0017] Figure 1 A schematic structural diagram of a silicon carbide MOS tube structure provided by an embodiment of the present invention.
[0018] Figure 2 A schematic diagram of the three-dimensional structure of a silicon carbide MOS tube structure provided by an embodiment of the present invention.
[0019] Figure 3 for Figure 2 Schematic diagram of the three-dimensional structure of the epitaxial region shown.
[0020] Figure 4 for Figure 3 Schematic top view of .
[0021] Figure 5 for Figure 2 Another schematic diagram of the three-dimensional structure of the epitaxial region is shown.
[0022] Figure 6 for Figure 5 The structural diagram of the AA direction is shown.
[0023] Figure 7 for Figure 5 The structural diagram of the BB direction is shown.
[0024] Figure 8 A schematic diagram of the three-dimensional structure of an epitaxial region of another silicon carbide MOS tube structure provided by an embodiment of the present invention.
[0025] Figure 9 forFigure 8 a top view schematic diagram.
[0026] Figure 10 is Figure 8 a cross-sectional view schematic diagram of the C-C direction. DETAILED DESCRIPTION
[0027] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all the other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application.
[0028] It should be noted that the terms "first", "second" and "one end" and the like in the specification and claims of the present application are used to distinguish similar objects, and do not necessarily indicate a specific order or a chronological sequence. It should be understood that the terms used in this way can be interchanged under appropriate circumstances, so that the embodiments of the application described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, system, product or device that includes a series of steps or units does not necessarily have to be limited to the clearly listed steps or units, but can include other steps or units that are not clearly listed or inherent to these processes, products or devices.
[0029] Referring to Figure 1 , Figure 2 and Figure 3 , the embodiments of the present application provide a silicon carbide MOS tube structure 10. The silicon carbide MOS tube structure 10 includes, for example, an epitaxial layer 110, a first body region 210 and a second body region 220, a first source region 121 and a second source region 122, an oxide layer 400 and a reinforcing layer 230.
[0030] Specifically, the epitaxial layer 110 has opposite first and second surfaces 101 and 102. The first and second body regions 210 and 220 are disposed within the epitaxial layer 110, the first and second body regions 210 and 220 are located on a side of the epitaxial layer 110 close to the second surface 102, the first and second body regions 210 and 220 are oppositely and spacedly disposed in a first direction, and the first and second body regions 210 and 220 extend along a second direction intersecting the first direction. Referring to Figure 3 The reinforcing layer 230 is located between the first and second body regions 210 and 220, and the reinforcing layer 230 extends along the first direction, referring to Figure 4 , Figure 5 , Figure 6 and Figure 7, the reinforcement layer 230 contacts the first body region 210, the second body region 220 and the epitaxial layer 110. The first direction and the second direction are Figure 2 The first source region 121 and the second source region 122 are embedded in the first body region 210 and the second body region 220. The first body region 210 blocks the first source region 121 and the epitaxial layer 110, and the second body region 220 blocks the second source region 122 and the epitaxial layer 110. The first source region 121 is disposed correspondingly to the first body region 210, and the second source region 122 is disposed correspondingly to the second body region 220.
[0031] See also Figure 2 The oxide layer 400 is located on the second surface 102 and extends along the second direction. The oxide layer 400 connects the epitaxial layer 110, the first body region 210, the second body region 220, the first source region 121, the second source region 122 and the reinforcement layer 230. The oxide layer 400 serves as an insulator and can be, for example, silicon dioxide. Figure 1 and Figure 2 Polysilicon 600 is disposed above the oxide layer 400. The first body region 210, the second body region 220, and the reinforcement layer 230 have the same doping concentration. The first body region 210, the second body region 220, and the reinforcement layer 230 have a first doping type, while the first source region 121, the second source region 122, and the epitaxial layer 110 have a second doping type. The first doping type is, for example, P-type, and the second doping type is, for example, N-type.
[0032] The silicon carbide MOS tube structure 10 provided in the embodiment of the present invention is provided as follows Figure 3 The reinforcement layer 230 shown strengthens the area of the partially conductive epitaxial layer 110 without affecting the channel width, thereby improving reliability and thus enhancing the stability of the silicon carbide MOS transistor structure 10.
[0033] Specifically, the channel width refers to the width of the conductive channel between the source and the drain in the structure of the silicon carbide MOS tube. In the embodiment of the present application, when the channel width remains unchanged, by setting the reinforcing layer 230, the epitaxial layer 110 has a partial area between the first body region 210 and the second body region 220 that is reinforced to increase the distribution of the electric field, so that the electric field is more uniform, and at the same time, the electric field intensity near the channel surface is reduced, thereby reducing the influence of the uneven electric field intensity on the silicon carbide MOS tube structure 10. The setting of the reinforcing layer 230 makes the electric field distribution more uniform, reduces the electric field peak near the channel surface, reduces the risk of breakdown of the oxide layer 400, thereby improving the reliability of the silicon carbide MOS tube structure 10, and since the first body region 210, the second body region 220 and the reinforcing layer 230 have the same doping concentration and the same doping type, it helps to ensure the consistency and stability of the structure. The embodiment of the present application optimizes the electric field distribution, reduces the electric field peak, reduces the influence of the uneven electric field intensity of the structure, and improves the reliability of the structure.
[0034] Further, referring to Figure 8 The number of reinforcing layers 230 is multiple, and the multiple reinforcing layers 230 are arranged and spaced apart in the second direction. The setting of multiple reinforcing layers 230 can disperse the electric field intensity to a larger area. By setting multiple reinforcing layers 230, each reinforcing layer 230 can share the load of the electric field, thereby reducing the electric field intensity on a single reinforcing layer and reducing the concentration of the electric field. The electric field can be dispersed between different layers and transmitted between them. This can reduce the intensity of the local electric field, reduce the risk of damage to the structure caused by the electric field, and at the same time reduce the electric field intensity near the channel surface, thereby reducing the influence of the uneven electric field intensity on the silicon carbide MOS tube structure 10, making the electric field distribution more uniform, reducing the electric field peak near the channel surface, reducing the risk of breakdown of the oxide layer 400, and further improving the reliability of the silicon carbide MOS tube structure 10.
[0035] Specifically, the spacing between two adjacent reinforcing layers 230 ranges from 0.1 to 10 microns. By setting an appropriate spacing, the electric field distribution between the reinforcing layers 230 can be adjusted. A smaller spacing can concentrate the electric field more, thereby improving the efficiency of current transmission, while a larger spacing can make the electric field distribution more uniform, thereby reducing the impact of the electric field on the structure. By adjusting the spacing, the electric field distribution can be optimized, improving the performance and reliability of the silicon carbide MOS tube structure 10. In addition, in high-density integrated circuits, the electric field between adjacent devices can interfere with each other, causing crosstalk effects. Setting an appropriate spacing can reduce the electric field coupling between adjacent reinforcing layers 230, thereby reducing the occurrence of crosstalk effects. This helps to improve the stability and reliability of the device. If the spacing between adjacent reinforcing layers 230 is too small, it can cause the structure to short circuit. An appropriate spacing setting can effectively prevent such short circuit conditions from occurring, ensuring the normal operation of the device. In summary, by setting the spacing between two adjacent reinforcing layers 230 within the range of 0.1 to 10 microns, the electric field distribution can be optimized, crosstalk effects can be reduced, and short circuit conditions can be prevented. This helps to improve the performance, reliability, and stability of the silicon carbide MOS tube structure 10.
[0036] Referring to Figure 8 , Figure 9 and Figure 10 , the silicon carbide MOS tube structure 10 further includes a buffer layer 130. The buffer layer 130 is disposed within the epitaxial layer 110, the buffer layer 130 is disposed between two adjacent reinforcing layers 230, the buffer layer 130 is of the second doping type, and the doping concentration of the buffer layer 130 is different from the doping concentration of the epitaxial layer 110. By setting the buffer layer 130, the difference in electric field intensity between the epitaxial layer 110 and the reinforcing layer 230 is reduced. Since the doping concentration of the buffer layer 130 is different from the doping concentration of the epitaxial layer 110, it can change the potential distribution between the epitaxial layer 110 and the reinforcing layer 230, thereby uniformizing the electric field distribution. Specifically, when there is a difference in electric field between the epitaxial layer 110 and the reinforcing layer 230, due to the presence of the buffer layer 130, the electric field will be distributed between the buffer layer 130 and the reinforcing layer 230, rather than being concentrated on the interface between the epitaxial layer 110 and the reinforcing layer 230. This way, the electric field gradient between the epitaxial layer 110 and the reinforcing layer 230 can be reduced, the electric field intensity is reduced, and the electric field distribution between the epitaxial layer 110 and the reinforcing layer 230 is optimized, thereby improving the stability of the silicon carbide MOS tube structure 10.
[0037] Further, the doping concentration of the buffer layer 130 is lower than the doping concentration of the first source region 121 and the second source region 122, and the doping concentration of the epitaxial layer 110 is lower than the doping concentration of the buffer layer 130. Since the doping concentration of the buffer layer 130 is lower than the doping concentration of the first source region 121 and the second source region 122, the buffer layer 130 plays a buffering role in the electric field distribution. When an external voltage is applied to the structure, a gradual potential peak is formed between the epitaxial layer 110 and the buffer layer 130, and the electric field is gradually distributed in the buffer layer 130, thereby blocking the influence of the electric field on the first source region 121 and the second source region 122. In this way, the influence of the electric field strength on the source region can be reduced, and the reliability of the silicon carbide MOS tube structure 10 can be improved. In addition, since the doping concentration of the epitaxial layer 110 is lower than the doping concentration of the buffer layer 130, the epitaxial layer 110 has a higher conductivity than the buffer layer 130. In this way, when an external voltage is applied to the structure, due to the higher conductivity of the epitaxial layer 110, the electric charge can flow more smoothly through the epitaxial layer 110, reducing the on-resistance and thereby reducing the heat generated when the silicon carbide MOS tube structure 10 as a power device is in forward conduction, thereby making the silicon carbide MOS tube structure 10 more reliable. At the same time, the low doping concentration of the epitaxial layer 110 also reduces the influence of impurity concentration on the conductivity, so such a setting not only reduces the influence of resistance, but also improves the reliability of the silicon carbide MOS tube structure 10. In summary, by setting the doping concentration of the buffer layer 130 to be lower than the doping concentration of the first source region 121 and the second source region 122, and the doping concentration of the epitaxial layer 110 to be lower than the doping concentration of the buffer layer 130, the difference in electric field strength can be reduced, thereby reducing the influence of the electric field on the source region, reducing the influence of resistance, and improving the reliability and stability of the silicon carbide MOS tube structure 10.
[0038] Specifically, the number of impurity atoms per cubic centimeter of the first body region 210 and the second body region 220 ranges from 10 17 The doping concentration of the buffer layer 130 ranges from 10 17 to 10 18 The thickness of the buffer layer 130 in the direction from the first surface 101 to the second surface 102 is, for example, less than the thickness of the reinforcing layer 230 in the direction from the first surface 101 to the second surface 102. Figure 8 , Figure 9 and Figure 10 When the reinforcing layer 230 is, for example,
[0039] The thickness of the buffer layer 130 in the direction from the first surface 101 to the second surface 102 is, for example, less than the thickness of the reinforcing layer 230 in the direction from the first surface 101 to the second surface 102.
[0040] Specifically, the doping concentration of the epitaxial layer 110 is, for example, in the order of 10 13 to 10 15 per cubic centimeter, the doping concentration of the buffer layer 130 is, for example, in the order of 10 17 to 10 19, and the doping concentration of the first source region 121 and the second source region 122 can be, for example, in the order of 10 19. By setting the buffer layer 130 with a higher doping concentration, the on-resistance of the silicon carbide MOS tube structure 10 can be reduced, thereby reducing the heat generated when the silicon carbide MOS tube structure 10 is in forward conduction as a power device, and thus making the silicon carbide MOS tube structure 10 more reliable.
[0041] The embodiment of the present application provides a manufacturing method of a silicon carbide MOS tube structure 10, comprising:
[0042] S1: referring to Figure 1 , an epitaxial layer 110 is generated by ion implantation, the epitaxial layer 110 has a first surface 101 and a second surface 102;
[0043] S2: a first body region 210, a second body region 220 and a reinforcing layer 230 are generated on the epitaxial layer 110 by ion implantation, the first body region 210 and the second body region 220 are located on the side of the epitaxial layer 110 close to the second surface 102, the first body region 210 and the second body region 220 are oppositely and spacedly arranged in a first direction, the first body region 210 and the second body region 220 extend along a second direction intersecting the first direction, the reinforcing layer 230 is located between the first body region 210 and the second body region 220, the reinforcing layer 230 extends along the first direction, and the reinforcing layer 230 is in contact with the first body region 210, the second body region 220 and the epitaxial layer 110;
[0044] S3: a first source region 121 is formed on the first body region 210, and a second source region 122 is formed on the second body region 220, the first source region 121 is located at one end of the first body region 210 close to the second surface 102, the second source region 122 is located at one end of the second body region 220 close to the second surface 102, and the first source region 121 and the second source region 122 extend along the second direction;
[0045] S4: an oxide layer 400 shown in Figure 1 is formed on the second surface 102 by a mask and etching method, the oxide layer 400 extends along the second direction, the oxide layer 400 connects the epitaxial layer 110, the first body region 210, the second body region 220, the first source region 121, the second source region 122 and the reinforcing layer 230, and the oxide layer 400 serves as an insulator, which can be, for example, silicon dioxide or the like;
[0046] The step of forming the first body region 210, the second body region 220 and the reinforcing layer 230 on the epitaxial layer 110 specifically comprises: forming a plurality of reinforcing layers 230 between the first body region 210 and the second body region 220, the plurality of reinforcing layers 230 being arranged and spaced apart in the second direction; wherein the first doping type is, for example, P type, and the second doping type is, for example, N type.
[0047] By implementing the method for manufacturing the silicon carbide MOS tube structure 10 provided in the embodiments of the present application, at least the silicon carbide MOS tube structure 10 as shown in Figure 1 may be obtained, and by changing the mask pattern in the corresponding step, the method for manufacturing the silicon carbide MOS tube structure 10 provided in the embodiments of the present application can obtain any one of the silicon carbide MOS tube structures 10 as shown in Figures 1 to 10 . The technical effects of the silicon carbide MOS tube structure 10 thus obtained are described in the embodiments of the present application.
[0048] Further, the method further comprises S5: forming a buffer layer 130 in the epitaxial layer 110, the buffer layer 130 extending in the direction from the first surface 101 to the second surface 102, the buffer layer 130 being arranged between two adjacent reinforcing layers 230, the buffer layer 130 having a doping concentration different from that of the epitaxial layer 110, and the buffer layer 130 being of the second doping type; for example, the buffer layer 130 as shown in Figure 9 may be formed by mask and ion implantation.
[0049] In addition, it can be understood that the foregoing embodiments are only exemplary descriptions of the present application, and the technical solutions of the various embodiments can be arbitrarily combined and used without conflict, contradiction or violation of the purpose of the present application.
[0050] Finally, it should be noted that: the foregoing embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: the technical solutions recorded in the foregoing embodiments can still be modified, or some technical features can be replaced by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.
Claims
1. A method for manufacturing a silicon carbide MOS tube structure, characterized in that: include: generating an epitaxial layer having a first surface and a second surface; Generating a first body region, a second body region, and a reinforcement layer on the epitaxial layer, wherein the first body region and the second body region are located on a side of the epitaxial layer close to the second surface, the first body region and the second body region are opposite to each other and spaced apart in a first direction, the first body region and the second body region extend along a second direction intersecting the first direction, the reinforcement layer is located between the first body region and the second body region, the reinforcement layer extends along the first direction, and the reinforcement layer is in contact with the first body region, the second body region, and the epitaxial layer; forming a first source region on the first body region and forming a second source region on the second body region, wherein the first source region is located at one end of the first body region close to the second surface, and the second source region is located at one end of the second body region close to the second surface, and the first source region and the second source region extend along the second direction; forming an oxide layer on the second surface, the oxide layer extending along the second direction, the oxide layer connecting the epitaxial layer, the first body region, the second body region, the first source region, the second source region, and the reinforcement layer; The doping concentrations of the first body region, the second body region and the reinforcement layer are the same; the doping types of the first body region, the second body region and the reinforcement layer are the first doping type, and the first source region, the second source region and the epitaxial layer are the second doping type.
2. The method for manufacturing a silicon carbide MOS tube structure according to claim 1, wherein: The steps of generating the first body region, the second body region and the reinforcement layer on the epitaxial layer specifically include: A plurality of reinforcement layers are formed between the first body region and the second body region, and the plurality of reinforcement layers are arranged in the second direction and spaced apart.
3. The method for manufacturing a silicon carbide MOS tube structure according to claim 2, wherein: Also includes: A buffer layer is generated in the epitaxial layer. The buffer layer is disposed between two adjacent reinforcement layers. The buffer layer is of the second doping type, and the doping concentration of the buffer layer is different from the doping concentration of the epitaxial layer.
4. The method for manufacturing a silicon carbide MOS tube structure according to claim 3, wherein: The doping concentration of the buffer layer is lower than the doping concentrations of the first source region and the second source region, and the doping concentration of the epitaxial layer is lower than the doping concentration of the buffer layer.
5. The method for manufacturing a silicon carbide MOS tube structure according to claim 2, wherein: The distance between two adjacent reinforcement layers ranges from 0.1 to 10 microns.
6. The method for manufacturing a silicon carbide MOS tube structure according to claim 3, wherein: The number of impurity atoms per cubic centimeter of the buffer layer is in the range of 10 17 ~10 18 .
7. The method for manufacturing a silicon carbide MOS tube structure according to claim 3, wherein: A thickness of the buffer layer in a direction from the first surface to the second surface is smaller than a thickness of the reinforcement layer in a direction from the first surface to the second surface.
8. The method for manufacturing a silicon carbide MOS tube structure according to claim 3, wherein: The distance between the buffer layer and the second surface is in a range of 0.1 to 10 micrometers.
9. A silicon carbide MOS tube structure, characterized in that: The silicon carbide MOS tube structure is manufactured by the method for manufacturing a silicon carbide MOS tube structure according to any one of claims 1 to 8.
10. A silicon carbide MOS tube structure, characterized in that: include: an epitaxial layer having opposing first and second surfaces; A first body region and a second body region are provided in the epitaxial layer, the first body region and the second body region are located on a side close to the second surface, the first body region and the second body region are opposite to each other and spaced apart in a first direction, and the first body region and the second body region extend along a second direction intersecting the first direction; a reinforcement layer, located between the first body region and the second body region, the reinforcement layer extending along the first direction, the reinforcement layer contacting the first body region, the second body region and the epitaxial layer; a first source region and a second source region, wherein the first source region is embedded in the first body region, the second source region is embedded in the second body region, the first source region is located at one end of the first body region close to the second surface, the second source region is located at one end of the second body region close to the second surface, and the first source region and the second source region extend along the second direction; an oxide layer located on the second surface and extending along the second direction, the oxide layer connecting the epitaxial layer, the first body region, the second body region, the first source region, the second source region, and the reinforcement layer; The first body region, the second body region and the reinforcement layer have the same doping concentration; the first body region, the second body region and the reinforcement layer are doped with P type, and the first source region, the second source region and the epitaxial layer are doped with N type.