Semiconductor device and method for manufacturing the same

Abstract

To provide a semiconductor device capable of obtaining good characteristics and a method for manufacturing such a semiconductor device.SOLUTION: According to one embodiment, a semiconductor device includes a silicon carbide member, a first member, a first layer, and a second layer. The silicon carbide member includes a first region. The first member includes silicon and oxygen. The first layer is provided between the first region and the first member. The first layer includes a bond between silicon and nitrogen. The second layer is provided between the first layer and the first member. The second layer includes a bond between silicon and oxygen and a bond between silicon and nitrogen.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] FIELD Embodiments of the present invention relate to a semiconductor device and a method for manufacturing the semiconductor device. [Background technology]

[0002] There are semiconductor devices such as transistors that use silicon carbide (SiC), and good characteristics are required for semiconductor devices. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2022-41725 Summary of the Invention [Problem to be solved by the invention]

[0004] The embodiments of the present invention provide a semiconductor device that can achieve good characteristics, and a method for manufacturing the semiconductor device. [Means for solving the problem]

[0005] According to an embodiment of the present invention, a semiconductor device includes a silicon carbide member including a first region, a first member including silicon and oxygen, and a first layer and a second layer. The first layer is provided between the first region and the first member. The first layer includes bonds between silicon and nitrogen. The second layer is provided between the first layer and the first member. The second layer includes bonds between silicon and oxygen and bonds between silicon and nitrogen. [Brief explanation of the drawings]

[0006] [Figure 1] FIG. 1 is a schematic cross-sectional view illustrating the semiconductor device according to the first embodiment. [Figure 2] FIG. 2 is a schematic cross-sectional view illustrating the semiconductor device according to the first embodiment. [Figure 3]FIG. 3 is a schematic cross-sectional view illustrating the semiconductor device according to the first embodiment. [Figure 4] 4A to 4C are schematic cross-sectional views illustrating the method for manufacturing the semiconductor device according to the second embodiment. [Figure 5] 5A to 5C are schematic cross-sectional views illustrating the method for manufacturing the semiconductor device according to the second embodiment. [Figure 6] 6A to 6C are schematic cross-sectional views illustrating the method for manufacturing the semiconductor device according to the second embodiment. [Figure 7] 7A to 7C are schematic cross-sectional views illustrating the method for manufacturing the semiconductor device according to the second embodiment. [Figure 8] 8A to 8C are schematic cross-sectional views illustrating the method for manufacturing the semiconductor device according to the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0007] Hereinafter, embodiments of the present invention will be described with reference to the drawings. The drawings are schematic or conceptual, and the relationship between the thickness and width of each part, the size ratio between parts, etc. are not necessarily the same as those in reality. Furthermore, even when the same part is shown, the dimensions and ratios may be different depending on the drawing. In the present specification and the drawings, elements similar to those described above with reference to the previous drawings are designated by the same reference numerals, and detailed descriptions thereof will be omitted as appropriate.

[0008] (First embodiment) FIG. 1 is a schematic cross-sectional view illustrating the semiconductor device according to the first embodiment. As shown in FIG. 1, a semiconductor device 110 according to the embodiment includes a silicon carbide member 30, a first member 10, a first layer 11, and a second layer 12.

[0009] The silicon carbide member 30 includes a first region 31. The silicon carbide member 30 may include, for example, 4H—SiC, 6H—SiC, or 3C—SiC.

[0010] The first member 10 includes silicon and oxygen. The first member 10 includes, for example, SiO2. The first layer 11 is provided between the first region 31 and the first member 10. As will be described later, the first layer 11 includes a bond between silicon and nitrogen. The first layer 11 includes SiN. The first layer 11 may further include a bond between silicon and carbon. For example, the first layer 11 may include SiCN.

[0011] The second layer 12 is provided between the first layer 11 and the first member 10. As will be described later, the second layer 12 includes a bond between silicon and oxygen and a bond between silicon and nitrogen. The second layer 12 includes, for example, SiON.

[0012] 1, the semiconductor device 110 may include a first conductive member 51. The first member 10 is provided between the first region 31 and the first conductive member 51. The first conductive member 51 is, for example, a gate electrode. In this case, the first member 10 functions as a gate insulating film.

[0013] As shown in FIG. 1, the direction from the first region 31 to the first member 10 is defined as a first direction D1. The thickness of the first layer 11 in the first direction D1 is defined as a first thickness t1. The first thickness t1 is, for example, 0.5 nm or less. The first thickness t1 may also be, for example, 0.3 nm or less.

[0014] The thickness of the second layer 12 in the first direction D1 is defined as a second thickness t2. The second thickness t2 is, for example, 1 nm or less. The second thickness t2 may be, for example, 0.7 nm or less. For example, the first thickness t1 is ½ or less of the second thickness t2 of the second layer.

[0015] The thickness t0 of the first member 10 in the first direction D1 is, for example, not less than 3 nm and not more than 100 nm. When the first member 10 functions as an insulating film, appropriate characteristics are obtained.

[0016] FIG. 2 is a schematic cross-sectional view illustrating the semiconductor device according to the first embodiment. As shown in FIG. 2, in one example, the first layer 11 is a layer including a silicon-nitrogen bond. This layer includes one Si layer and one C layer. The one Si layer and the one C layer overlap in the first direction D1. The first layer 11 is, for example, a termination layer. As already described, the first layer 11 may further include a silicon-carbon bond.

[0017] 2, the second layer 12 includes a first oxygen 81O, a second silicon 81b, and a first nitrogen 81N. The first oxygen 81O is bonded to the first silicon 81a. The first silicon 81a may be included in the first layer 11 or the second layer 12.

[0018] The second silicon 81b bonds with the first oxygen 810. The first nitrogen 81N bonds with the second silicon 81b and the third silicon 81c. The third silicon 81c may be included in the second layer 12 or the first member .

[0019] The direction from the first silicon 81a to the second silicon 81b includes a component in a first direction from the first region 31 (silicon carbide member 30) to the first member 10. The direction from the second silicon 81b to the third silicon 81c includes a component in the first direction. The direction from the first oxygen 81O to the first nitrogen includes a component in the first direction. The second layer 12 is, for example, a transition layer.

[0020] By providing such a first layer 11 and a second layer 12, the interface state density between the first region 31 and the first member 10 can be reduced.

[0021] For example, the nitrogen termination rate can be improved at the interface between the first region 31 and the first member 10. For example, a good interface can be obtained. For example, oxygen is replaced with nitrogen at the surface of SiC. First bonds are generated at the surface. Second dangling bonds included in the first member 10 are connected to the first bonds. This suppresses the presence of dangling bonds.

[0022] For example, oxidation is suppressed in the first region 31. Introduction of unnecessary nitrogen is suppressed in the first region 31. In the embodiment, for example, at the interface between the gate insulating film and the semiconductor, the termination rate of dangling bonds by nitrogen can be improved. The interface state density is reduced. For example, the reliability of the insulating film is improved.

[0023] In the embodiment, the first layer 11 is, for example, a termination layer containing nitrogen at a high concentration. The second layer 12 is, for example, a transition layer containing silicon, nitrogen, and oxygen. In the embodiment, oxidation in the first region is suppressed. Stable nitrogen termination is obtained. The presence of dangling bonds between the first member 10 is suppressed.

[0024] For example, there is a first reference example in which a silicon oxide film is formed on a SiC layer and then heat-treated in an atmosphere containing NO or the like. In the first reference example, nitrogen is introduced through the silicon oxide film into the interface between the SiC layer and the silicon oxide film. In this case, oxidation of the SiC layer, which should be avoided, occurs. Unnecessary nitrogen is introduced into the SiC layer. This makes it difficult to obtain the desired characteristics.

[0025] In the embodiment, oxidation of the first region 31 of SiC, which should be avoided, is suppressed. Introduction of unnecessary nitrogen into the first region 31 of SiC is suppressed. Targeted characteristics are easily obtained. In the embodiment, introduction of unnecessary nitrogen into the first member 10 is suppressed. Trapping in the first member 10 is suppressed.

[0026] In the embodiment, for example, the first region 31 does not contain nitrogen. Alternatively, the concentration of nitrogen contained in the first region 31 is 1 / 10 of the concentration of nitrogen contained in the first layer 11. 5 In one example, the concentration of nitrogen contained in the first region 31 is less than 5×10 16 cm -3 The concentration of nitrogen contained in the first region 31 is 1×10 16 cm -3 The following is also fine.

[0027] In the embodiment, for example, the first member 10 does not contain nitrogen. Alternatively, the concentration of nitrogen contained in the first member 10 is 1 / 10 of the concentration of nitrogen contained in the first layer 11. 2 In one example, the concentration of nitrogen contained in the first member 10 is less than 5×10 19 cm -3 The concentration of nitrogen contained in the first member 10 is 1×10 19 cm -3 The concentration of nitrogen contained in the first member 10 may be 5×10 18 cm -3 The concentration of nitrogen contained in the first member 10 may be 1×10 18 cm -3 The following is also fine.

[0028] FIG. 3 is a schematic cross-sectional view illustrating the semiconductor device according to the first embodiment. 3, the semiconductor device 111 according to the embodiment includes a first conductive member 51, a second conductive member 52, and a third conductive member 53. The remaining configuration of the semiconductor device 111 may be the same as the configuration of the semiconductor device 110.

[0029] As shown in FIG. 3, the first member 10 is provided between a first region 31 and a first conductive member 51. The silicon carbide member 30 further includes a second region 32 and a third region 33. The first region 31 is of a first conductivity type. The second region 32 is of a second conductivity type. The third region 33 is of the first conductivity type. The first conductivity type is one of n-type and p-type. The second conductivity type is the other of n-type and p-type. Hereinafter, the first conductivity type is referred to as n-type, and the second conductivity type is referred to as p-type.

[0030] The first region 31 and the third region 33 contain impurities of the first conductivity type, such as N. The second region 32 contains impurities of the second conductivity type, such as Al. The concentration of the impurities of the first conductivity type (e.g., carrier concentration) in the third region 33 is higher than the concentration of the impurities of the first conductivity type (e.g., carrier concentration) in the first region 31.

[0031] At least a portion of the second region 32 is located between the first region 31 and the third region 33. The second conductive member 52 is electrically connected to the third region 33. The third conductive member 53 is electrically connected to the first region 31. An insulating member 40 may be provided between the first conductive member 51 and the second conductive member 52.

[0032] The current flowing between the third conductive member 53 and the second conductive member 52 can be controlled by the potential of the first conductive member 51. The potential of the first conductive member 51 is, for example, a potential based on the potential of the second conductive member 52. The second conductive member 52 functions, for example, as a source electrode. The third conductive member 53 functions, for example, as a drain electrode. The first conductive member 51 functions, for example, as a gate electrode. The first member 10 functions, for example, as a gate insulating film. The semiconductor device 111 is, for example, a MOS transistor.

[0033] The direction from the third conductive member 53 to the first conductive member 51 is along the first direction D1. The first direction D1 is, for example, the Z-axis direction. A direction perpendicular to the Z-axis direction is defined as the X-axis direction. A direction perpendicular to the Z-axis direction and the X-axis direction is defined as the Y-axis direction.

[0034] As shown in FIG. 3, the first region 31 includes a first partial region 31a and a second partial region 31b. In the first direction D1, the first partial region 31a is located between the third conductive member 53 and the first conductive member. The direction from the first partial region 31a to the second partial region 31b is along the second direction D2. The second direction D2 is, for example, the X-axis direction. The second partial region 31b is located between a portion of the third conductive member 53 and a portion of the first conductive member 51 in the first direction D1.

[0035] In the second direction D2, a part of the second region 32 is located between a part of the first region 31 (first partial region 31a) and the third region 33. In the first direction D1, another part of the second region 32 is located between the second partial region 31b and the second conductive member 52.

[0036] 3, the silicon carbide member 30 may include a fourth region 34. The fourth region 34 is p-type. In the second direction D2, a part of the second region 32 is located between a part of the first region 31 (first partial region 31a) and the fourth region 34. In the second direction D2, the third region 33 is located between the part of the second region 32 and the fourth region 34.

[0037] As shown in FIG. 3 , the silicon carbide member 30 may include a fifth region 35. The fifth region 35 is of the first conductivity type. The fifth region 35 is located between the third conductive member 53 and the first region 31 in the first direction D1. The concentration of impurities of the first conductivity type (e.g., carrier concentration) in the fifth region 35 is higher than the concentration of impurities of the first conductivity type (e.g., carrier concentration) in the first region 31. By providing the fifth region 35, low resistance can be obtained in the electrical connection between the first region 31 and the third conductive member 53.

[0038] (Second embodiment) The second embodiment relates to a method for manufacturing a semiconductor device. An example of a method for manufacturing the semiconductor device 110 will be described below.

[0039] 4 to 7 are schematic cross-sectional views illustrating the method for manufacturing the semiconductor device according to the second embodiment. As shown in Fig. 4, a first process T1 is performed in which the silicon carbide member 30 is heat-treated in a first atmosphere. Before the first process T1, a process using high-temperature hydrogen may be performed. The high-temperature hydrogen process etches the surface of the silicon carbide member 30, removing surface portions containing impurities. After this, the first process T1 is performed.

[0040] The first treatment T1 forms a first layer 11 and a second film 12f on the surface portion of the silicon carbide member 30. The first layer 11 includes bonds between silicon and nitrogen. In this example, the first layer 11 further includes bonds between silicon and carbon. The second film 12f includes bonds between silicon and oxygen. The first layer 11 is located between the silicon carbide member 30 and the second film 12f.

[0041] The first atmosphere contains nitrogen. The first treatment T1 is, for example, annealing in an atmosphere containing nitrogen. The first treatment T1, for example, suppresses the formation of an oxide film on the surface of the silicon carbide member 30. The first atmosphere may contain a trace amount of oxygen to protect the chamber. The concentration of oxygen in the first atmosphere is, for example, 1000 ppm or less. The oxygen concentration of 1000 ppm or less suppresses the formation of an oxide film.

[0042] The first process T1 may be performed, for example, in a chamber for epitaxial growth, and the temperature of the first process T1 may be, for example, 1000° C. to 1500° C. The duration of the first process T1 may be, for example, 1 minute to 1 hour.

[0043] 5, after the first process T1, a second process T2 is performed. The second process T2 includes heat-treating the silicon carbide member 30 in a second atmosphere containing nitrogen and oxygen. For example, the second atmosphere includes at least one selected from the group consisting of NO and NO. By the second process T2, for example, oxygen on the surface of the second film 12f is replaced with nitrogen.

[0044] The second treatment T2 may be performed, for example, in a thermal diffusion chamber. The temperature of the second treatment T2 may be, for example, 1000°C to 1400°C. The time of the second treatment T2 may be, for example, 1 minute to 1 hour. The temperature of the second treatment T2 may be, for example, 1100°C to 1300°C.

[0045] As shown in FIG. 6, the first member 10 is formed on the silicon carbide member 30 (second film 12f) after the second treatment T2. The first member 10 includes silicon and oxygen. The first member 10 includes, for example, SiO2. The first member 10 is formed by, for example, chemical vapor deposition (CVD). The chemical vapor deposition may include plasma enhanced chemical vapor deposition (PE-CVD). The chemical vapor deposition may include atomic layer deposition (ALD).

[0046] As shown in FIG. 7, a third process T3 is performed in which the stacked body SB1 including the silicon carbide member 30 and the first member 10 is heat-treated in a third atmosphere. The third atmosphere contains nitrogen and oxygen. The third process T3 causes nitrogen on the surface of the second film 12f to bond with silicon contained in the first member 10. This forms the second layer 12. A good interface is formed.

[0047] The third atmosphere may contain at least one selected from the group consisting of NO and NO. The third treatment T3 may be performed, for example, in a thermal diffusion chamber. The temperature of the third treatment T3 may be, for example, 1000°C or higher and 1400°C or lower. The time of the third treatment T3 may be, for example, 1 minute or higher and 1 hour or lower. The temperature of the third treatment T3 may be, for example, 1100°C or higher and 1300°C or lower.

[0048] As described above, oxygen on the surface of the second film 12f is replaced with nitrogen by the second treatment T2. As a result, in the third treatment T3, the nitrogen on the surface of the second film 12f bonds with silicon contained in the first member 10. On the other hand, a second reference example can be considered in which the second treatment T2 is not performed. In the second reference example, oxygen is present on the surface of the second film 12f. In the second reference example, this oxygen does not bond with silicon contained in the first member 10 in the third treatment T3. As a result, dangling bonds remain. The dangling bonds form interface states. In the second reference example, it is difficult to obtain the desired characteristics.

[0049] 8A to 8C are schematic cross-sectional views illustrating the method for manufacturing the semiconductor device according to the second embodiment. Fig. 8 corresponds to another example of the process illustrated in Fig. 4. As shown in Fig. 8, the first layer 11 includes bonds between silicon and nitrogen. At least a portion of the first layer 11 may be substantially free of bonds between silicon and carbon. In this case, too, a good interface is formed by the second layer 12 provided on such a first layer 11.

[0050] In embodiments, information regarding the elemental composition of silicon carbide components, components, and layers may be obtained by electron microscopy, such as scanning transmission electron microscopy-energy dispersive spectroscopy (STEM-EDS) elemental mapping, or high-angle annular dark field (HAADF) STEM imaging.

[0051] The embodiment may include the following configurations (e.g., technical solutions). (Configuration 1 ) a silicon carbide member including a first region; a first member containing silicon and oxygen; a first layer provided between the first region and the first member, the first layer including a bond between silicon and nitrogen; a second layer provided between the first layer and the first member, the second layer including a bond between silicon and oxygen and a bond between silicon and nitrogen; A semiconductor device comprising:

[0052] (Configuration 2) 2. The semiconductor device of claim 1, wherein the first layer has a first thickness of 0.5 nm or less in a first direction from the first region to the first member.

[0053] (Configuration 3) 3. The semiconductor device of claim 2, wherein the first thickness is 0.3 nm or less.

[0054] (Configuration 4) 4. The semiconductor device of claim 2, wherein the second layer has a second thickness in the first direction of 1 nm or less.

[0055] (Configuration 5) 5. The semiconductor device of claim 4, wherein the second thickness is 0.7 nm or less.

[0056] (Configuration 6) 6. The semiconductor device according to any one of configurations 1 to 5, wherein the first layer is a two-atom layer containing the bond between silicon and nitrogen.

[0057] (Configuration 7 ) The second layer is a first oxygen bonded to a first silicon; a second silicon bonded to the first oxygen; a first nitrogen bonded to the second silicon and the third silicon; Including, a direction from the first silicon to the second silicon includes a component of a first direction from the first region to the first member; 7. The semiconductor device according to any one of configurations 1 to 6, wherein the direction from the second silicon to the third silicon includes a component in the first direction.

[0058] (Configuration 8) 2. The semiconductor device of claim 1, wherein a first thickness of the first layer in a first direction from the first region to the first member is less than or equal to half a second thickness of the second layer in the first direction.

[0059] (Configuration 9) the first region is nitrogen-free, or The concentration of nitrogen contained in the first region is 1 / 10 of the concentration of nitrogen contained in the first layer. 5 9. The semiconductor device according to any one of configurations 1 to 8, wherein the thickness is less than 100 μm.

[0060] (Configuration 10) The concentration of nitrogen contained in the first region is 5×10 16 cm -3 10. The semiconductor device according to configuration 9, wherein:

[0061] (Configuration 11) the first component does not contain nitrogen, or The concentration of nitrogen contained in the first member is 1 / 10 of the concentration of nitrogen contained in the first layer. 211. The semiconductor device according to any one of configurations 1 to 10, wherein the semiconductor device has a capacitance of less than 100 Ω / cm.

[0062] (Configuration 12) The concentration of nitrogen contained in the first member is 5×10 19 cm -3 12. The semiconductor device according to claim 11, wherein:

[0063] (Configuration 13) Further comprising a first conductive member; 13. The semiconductor device according to any one of configurations 1 to 12, wherein the first member is provided between the first region and the first conductive member.

[0064] (Configuration 14) Further comprising a first conductive member, a second conductive member and a third conductive member, the first member is provided between the first region and the first conductive member, the silicon carbide member further includes a second region and a third region; the first region is of a first conductivity type; the second region is of a second conductivity type; the third region is of the first conductivity type; At least a portion of the second region is between the first region and the third region, the second conductive member is electrically connected to the third region; 9. The semiconductor device according to any one of configurations 1 to 8, wherein the third conductive member is electrically connected to the first region.

[0065] (Configuration 15) performing a first process of heat treating the silicon carbide member in a first atmosphere; performing a second process after the first process by heat treating the silicon carbide member in a second atmosphere containing nitrogen and oxygen; forming a first member containing silicon and oxygen on the silicon carbide member after the second treatment; a third process for heat-treating a stacked body including the silicon carbide member and the first member in a third atmosphere including nitrogen and oxygen;

[0066] (Configuration 16) 16. The method of claim 15, wherein the second atmosphere contains at least one selected from the group consisting of NO and N2O.

[0067] (Configuration 17) 17. The method for manufacturing a semiconductor device according to claim 15, wherein the third atmosphere contains at least one selected from the group consisting of NO and N2O.

[0068] (Configuration 18) the first atmosphere includes nitrogen; 18. The method for manufacturing a semiconductor device according to any one of configurations 15 to 17, wherein the concentration of oxygen in the first atmosphere is 1000 ppm or less.

[0069] (Configuration 19) 19. The method for manufacturing a semiconductor device according to any one of configurations 15 to 18, further comprising forming a first conductive member on the first member after the third treatment.

[0070] (Configuration 20) The laminate is a first layer disposed between the silicon carbide member and the first member, the first layer including bonds between silicon and nitrogen; a second layer provided between the first layer and the first member, the second layer including a bond between silicon and oxygen and a bond between silicon and nitrogen; 20. The method for manufacturing a semiconductor device according to any one of configurations 15 to 19, comprising:

[0071] According to the embodiments, a semiconductor device that can obtain good characteristics and a method for manufacturing the semiconductor device are provided.

[0072] In this specification, "vertical" and "parallel" do not only mean strictly vertical and strictly parallel, but also include variations in the manufacturing process, and may mean substantially vertical and substantially parallel.

[0073] The embodiments of the present invention have been described above with reference to specific examples. However, the present invention is not limited to these specific examples. For example, the specific configurations of the elements included in the semiconductor device, such as silicon carbide members, members, layers, and conductive members, are within the scope of the present invention as long as a person skilled in the art can implement the present invention in a similar manner and obtain similar effects by appropriately selecting them from known ranges.

[0074] Furthermore, any combination of two or more elements of each specific example within the scope of technical feasibility is also included within the scope of the present invention as long as it includes the gist of the present invention.

[0075] In addition, all semiconductor devices and semiconductor device manufacturing methods that can be implemented by a person skilled in the art by making appropriate design modifications based on the semiconductor device and semiconductor device manufacturing method described above as embodiments of the present invention also fall within the scope of the present invention, as long as they include the gist of the present invention.

[0076] In addition, within the scope of the concept of the present invention, a person skilled in the art may come up with various modifications and alterations, and it will be understood that these modifications and alterations also fall within the scope of the present invention.

[0077] Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, and are also included in the scope of the invention and its equivalents as defined in the claims. [Explanation of symbols]

[0078] 10...first member, 11, 12...first and second layers, 12f...film, 30...silicon carbide member, 31-35...first to fifth regions, 31a, 31b...first and second partial regions, 40...insulating member, 51-53...first to third conductive members, 81N...first nitrogen, 81O...first oxygen, 81a-81c...first to third silicon, 110, 111...semiconductor device, D1, D2...first and second directions, SB1...laminated body, T1-T3...first to third treatments, t0...thickness, t1, t2...thickness

Claims

1. a silicon carbide member including a first region; a first member including silicon and oxygen; a first layer provided between the first region and the first member, the first layer including a bond between silicon and nitrogen; a second layer provided between the first layer and the first member, the second layer including a bond between silicon and oxygen and a bond between silicon and nitrogen; Equipped with a first silicon at the boundary between the first layer and the second layer is bonded to nitrogen contained in the first layer and carbon contained in the first layer; the first silicon is bonded to the first oxygen contained in the second layer; the first oxygen bonds with the second silicon contained in the second layer; the second silicon is bonded to the first nitrogen contained in the second layer; the first nitrogen bonds with third silicon at the interface of the second layer and the first member; the third silicon bonds with oxygen contained in the first member, the nitrogen contained in the first layer bonds with silicon at the boundary between the silicon carbide member and the first layer, and the carbon contained in the first layer bonds with another silicon at the boundary between the silicon carbide member and the first layer.

2. The semiconductor device according to claim 1 , wherein a first thickness of said first layer in a first direction from said first region to said first member is 0.5 nm or less.

3. The semiconductor device according to claim 2 , wherein the first thickness is 0.3 nm or less.

4. The semiconductor device according to claim 2 , wherein the second thickness of the second layer in the first direction is 1 nm or less.

5. The semiconductor device according to claim 4 , wherein the second thickness is 0.7 nm or less.

6. a direction from the first silicon to the second silicon includes a component of a first direction from the first region to the first member; The semiconductor device according to claim 1 , wherein the direction from the second silicon to the third silicon includes a component in the first direction.

7. 2. The semiconductor device according to claim 1, wherein a first thickness of the first layer in a first direction from the first region to the first member is equal to or less than half a second thickness of the second layer in the first direction.

8. the first region is nitrogen-free; or The concentration of nitrogen contained in the first region is 1 / 10 of the concentration of nitrogen contained in the first layer. ５ The semiconductor device according to claim 1 , wherein the thickness is less than 100 μm.

9. The concentration of nitrogen contained in the first region is 5×10 １６ cm －３ 9. The semiconductor device according to claim 8, wherein:

10. the first component is nitrogen-free; or The concentration of nitrogen contained in the first member is 1 / 10 of the concentration of nitrogen contained in the first layer. ２ The semiconductor device according to claim 1 , wherein the thickness is less than 100 μm.

11. The concentration of nitrogen contained in the first member is 5×10 １９ cm －３ 11. The semiconductor device according to claim 10, wherein:

12. Further comprising a first conductive member; The semiconductor device according to claim 1 , wherein the first member is provided between the first region and the first conductive member.

13. further comprising a first conductive member, a second conductive member, and a third conductive member; the first member is provided between the first region and the first conductive member, the silicon carbide member further includes a second region and a third region; the first region is of a first conductivity type; the second region is of a second conductivity type; the third region is of the first conductivity type; At least a portion of the second region is between the first region and the third region, the second conductive member is electrically connected to the third region; The semiconductor device according to claim 1 , wherein said third conductive member is electrically connected to said first region.

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