Semiconductor device and method for manufacturing the same

Abstract

To provide a semiconductor device with stable characteristics and a manufacturing method thereof.SOLUTION: A semiconductor device according to an embodiment includes first to third electrodes and a semiconductor member. The first semiconductor layer includes Alx1Ga1-x1N (0≤x1<1). The second semiconductor layer includes Alx2Ga1-x2N (0<x2<1, x1<x2). The third semiconductor layer includes Al, Ga, and N. At least a portion of the third semiconductor layer is provided between a third semiconductor portion of the second semiconductor layer and at least a portion of a second electrode portion of the second electrode. The third semiconductor layer includes a first portion including Aly1Ga1-y1N (0<y1≤1) and a second portion including Aly2Ga1-y2N (0≤y2<1, y2<y1). The second portion is between the first portion and at least a portion of the second electrode portion.SELECTED DRAWING: Figure 1

Description

Technical Field

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

Background Art

[0002] For example, in a semiconductor device, stable characteristics are desired.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Embodiments of the present invention provide a semiconductor device and a method for manufacturing the same that can stabilize characteristics.

Means for Solving the Problems

[0005] According to an embodiment of the present invention, a semiconductor device includes a first electrode, a second electrode, a third electrode, and a semiconductor member. The direction from the first electrode to the second electrode follows a first direction. The second electrode includes a first electrode portion and a second electrode portion. The second electrode portion is connected to the first electrode portion. The position of the third electrode in the first direction is between the position of the first electrode in the first direction and the position of the second electrode in the first direction. The semiconductor member includes a first semiconductor layer, a second semiconductor layer, and a third semiconductor layer. The first semiconductor layer is Al x1 Ga 1-x1It includes N(0≦x1<1). The first semiconductor layer includes a first partial region, a second partial region, a third partial region, a fourth partial region, a fifth partial region, and a sixth partial region. The second direction from the first partial region to the first electrode intersects with the first direction. The direction from the second partial region to the first electrode portion is along the second direction. The direction from the sixth partial region to the second electrode portion is along the second direction. The direction from the third partial region to the third electrode is along the second direction. The position of the fourth partial region in the first direction is between the position of the first partial region in the first direction and the position of the third partial region in the first direction. The position of the fifth partial region in the first direction is between the position of the third partial region in the first direction and the position of the second partial region in the first direction. The position of the sixth partial region in the first direction is between the position of the fifth partial region in the first direction and the position of the second partial region in the first direction. The second semiconductor layer contains Al x2 Ga 1-x2 It contains N(0<x2<1, x1<x2). The second semiconductor layer includes a first semiconductor portion, a second semiconductor portion, and a third semiconductor portion. The direction from the fourth partial region to the first semiconductor portion is along the second direction. The direction from the fifth partial region to the second semiconductor portion is along the second direction. The direction from the sixth partial region to the third semiconductor portion is along the second direction. The third semiconductor layer contains Al, Ga, and N. At least a part of the third semiconductor layer is provided between the third semiconductor portion and at least a part of the second electrode portion in the second direction. The third semiconductor layer contains Al y1 Ga 1-y1 It includes a first part containing N(0<y1≦1) and Al y2 Ga 1-y2 It includes a second part containing N(0≦y2<1, y2<y1). The second part is between the first part and at least a part of the second electrode portion.

Brief Description of the Drawings

[0006] [Figure 1] FIG. 1 is a schematic cross-sectional view illustrating a semiconductor device according to the first embodiment. [Figure 2] Figure 2 is a schematic plan view illustrating a semiconductor device according to the first embodiment. [Figure 3] Figure 3 is a schematic diagram illustrating a semiconductor device according to the first embodiment. [Figure 4] Figure 4 is a schematic diagram illustrating a semiconductor device according to the first embodiment. [Figure 5] Figure 5 is a schematic diagram illustrating a semiconductor device according to the first embodiment. [Figure 6] Figure 6 is a schematic diagram illustrating a semiconductor device according to the first embodiment. [Figure 7] Figure 7 is a schematic cross-sectional view illustrating a semiconductor device according to the first embodiment. [Figure 8] Figure 8 is a schematic cross-sectional view illustrating a semiconductor device according to the first embodiment. [Figure 9] Figures 9(a) to 9(c) are schematic diagrams illustrating a semiconductor device according to the first embodiment. [Figure 10] Figures 10(a) to 10(c) are schematic diagrams illustrating a semiconductor device according to the first embodiment. [Figure 11] Figure 11 is a schematic cross-sectional view illustrating a semiconductor device according to the first embodiment. [Figure 12] Figure 12 is a schematic cross-sectional view illustrating a semiconductor device according to the first embodiment. [Figure 13] Figure 13 is a schematic cross-sectional view illustrating a semiconductor device according to the first embodiment. [Figure 14] Figure 14 is a schematic cross-sectional view illustrating a semiconductor device according to the first embodiment. [Figure 15] Figures 15(a) to 15(c) are schematic cross-sectional views illustrating a method for manufacturing a semiconductor device according to the second embodiment. [Figure 16] Figures 16(a) and 16(b) are schematic cross-sectional views illustrating a method for manufacturing a semiconductor device according to the second embodiment. [Modes for carrying out the invention]

[0007] Embodiments of the present invention will be described below with reference to the drawings. Drawings are schematic or conceptual, and the relationships between the thickness and width of each part, as well as the ratios of the sizes of different parts, are not necessarily identical to those of reality. Even when representing the same part, the dimensions and ratios may be depicted differently in different drawings. In this specification and in each figure, elements similar to those described above are denoted by the same reference numerals with respect to previously shown figures, and detailed explanations are omitted as appropriate.

[0008] (First Embodiment)

[0009] Figure 1 is a schematic cross-sectional view illustrating a semiconductor device according to the first embodiment. Figure 2 is a schematic plan view illustrating a semiconductor device according to the first embodiment. Figure 1 is a cross-sectional view taken along the line A1-A2 in Figure 2.

[0010] As shown in Figures 1 and 2, the semiconductor device 110 according to this embodiment includes a first electrode 51, a second electrode 52, a third electrode 53, and a semiconductor member 10M.

[0011] The direction from the first electrode 51 to the second electrode 52 is along the first direction D1. The first direction D1 is defined as the X-axis direction. One direction perpendicular to the X-axis direction is defined as the Z-axis direction. The directions perpendicular to both the X-axis direction and the Z-axis direction are defined as the Y-axis direction.

[0012] As shown in Figure 1, the second electrode 52 includes a first electrode portion 52a and a second electrode portion 52b. The second electrode portion 52b is connected to the first electrode portion 52a.

[0013] The position of the third electrode 53 in the first direction D1 is between the position of the first electrode 51 in the first direction D1 and the position of the second electrode 52 in the first direction D1.

[0014] The semiconductor component 10M includes a first semiconductor layer 10, a second semiconductor layer 20, and a third semiconductor layer 30.

[0015] The first semiconductor layer 10 contains Al x1 Ga 1-x1 N (0 ≦ x1 < 1). The composition ratio x1 is, for example, not less than 0 and less than 0.15. The first semiconductor layer 10 may be, for example, a GaN layer.

[0016] The first semiconductor layer 10 includes a first partial region 11, a second partial region 12, a third partial region 13, a fourth partial region 14, a fifth partial region 15, and a sixth partial region 16. A second direction D2 from the first partial region 11 to the first electrode 51 intersects a first direction D1. The second direction D2 may be, for example, the Z-axis direction.

[0017] The direction from the second partial region 12 to the first electrode portion 52a is along the second direction D2. The direction from the sixth partial region 16 to the second electrode portion 52b is along the second direction D2. The direction from the third partial region 13 to the third electrode 53 is along the second direction D2.

[0018] The position of the fourth partial region 14 in the first direction D1 is between the position of the first partial region 11 in the first direction D1 and the position of the third partial region 13 in the first direction D1. The position of the fifth partial region 15 in the first direction D1 is between the position of the third partial region 13 in the first direction D1 and the position of the second partial region 12 in the first direction D1. The position of the sixth partial region 16 in the first direction D1 is between the position of the fifth partial region 15 in the first direction D1 and the position of the second partial region 12 in the first direction D1.

[0019] The second semiconductor layer 20 contains Al x2 Ga 1-x2 N (0 < x2 < 1, x1 < x2). The composition ratio x2 may be, for example, not less than 0.15 and not more than 0.4. The second semiconductor layer 20 is, for example, an AlGaN layer.

[0020] The second semiconductor layer 20 includes a first semiconductor portion 21, a second semiconductor portion 22, and a third semiconductor portion 23. The direction from the fourth partial region 14 to the first semiconductor portion 21 is along the second direction D2. The direction from the fifth partial region 15 to the second semiconductor portion 22 is along the second direction D2. The direction from the sixth partial region 16 to the third semiconductor portion 23 is along the second direction D2.

[0021] The third semiconductor layer 30 includes, for example, Al, Ga, and N. The third semiconductor layer 30 may be, for example, an AlGaN layer. At least a part of the third semiconductor layer 30 is provided between the third semiconductor portion 23 and at least a part of the second electrode portion 52b in the second direction D2.

[0022] The third semiconductor layer 30 includes, for example, a first portion 31 and a second portion 32. The first portion 31 contains Al y1 Ga 1-y1 N (0 < y1 ≤ 1). The second portion 32 contains Al y2 Ga 1-y2 N (0 ≤ y2 < 1, y2 < y1). The second portion 32 is between the first portion 31 and at least a part of the second electrode portion 52b. The composition ratio y1 may be, for example, 0.15 or more and 0.8 or less. The composition ratio y2 may be, for example, 0 or more and less than 0.15.

[0023] The current flowing between the first electrode 51 and the second electrode 52 can be controlled by the potential of the third electrode 53. The potential of the third electrode 53 may be, for example, a potential based on the potential of the first electrode 51. The first electrode 51 functions as, for example, a source electrode. The second electrode 52 functions as, for example, a drain electrode. The third electrode 53 functions as, for example, a gate electrode. The semiconductor device 110 is, for example, a transistor.

[0024] The first semiconductor layer 10 includes a portion facing the second semiconductor layer 20. A carrier region 10c is formed in this portion. The carrier region 10c is, for example, a two-dimensional electron gas. The semiconductor device 110 is, for example, a HEMT (High Electron Mobility Transistor).

[0025] For example, the distance along the first direction D1 between the first electrode 51 and the third electrode 53 is shorter than the distance along the first direction D1 between the third electrode 53 and the second electrode 52. This makes it easier to obtain stable operation.

[0026] As described above, in this embodiment, the second electrode 52 is provided with a first electrode portion 52a and a second electrode portion 52b. For example, the first electrode portion 52a may be in contact with the second semiconductor layer 20. The position of the second electrode portion 52b in the first direction D1 is between the position of the third electrode 53 in the first direction D1 and the position of the first electrode portion 52a in the first direction D1. For example, the third semiconductor layer 30 is provided below at least a part of the second electrode portion 52b. The direction from the third semiconductor layer 30 to the first electrode portion 52a is along the first direction D1. The second electrode portion 52b is, for example, an overhang portion.

[0027] As described above, a third semiconductor layer 30 is provided between the third semiconductor portion 23 and the second electrode portion 52b. The third semiconductor layer 30 includes a first portion 31 with a high Al composition ratio and a second portion 32 with a low Al composition ratio. For example, the first portion 31 is the portion in contact with the third semiconductor portion 23. The second portion 32 is the portion in contact with the second electrode portion 52b.

[0028] In this embodiment, the electric field is mitigated by providing a third semiconductor layer 30 between the third semiconductor portion 23 and the second electrode portion 52b. This makes it easier to obtain a high breakdown voltage.

[0029] In the first reference example, an insulating layer is provided between the third semiconductor portion 23 and the second electrode portion 52b. In this case as well, the electric field is relaxed. However, in the first reference example, carrier traps are easily formed in the insulating layer. Carriers accumulated in the traps become fixed, and the operation tends to become unstable. For example, the on-resistance tends to increase during operation.

[0030] In this embodiment, a semiconductor layer (third semiconductor layer 30) is provided between the third semiconductor portion 23 and the second electrode portion 52b. For example, even if the semiconductor layer (third semiconductor layer 30) includes traps, carriers trapped in the traps can move. This suppresses operational instability. For example, an increase in on-resistance during operation can be suppressed. In this embodiment, a semiconductor device with stabilized characteristics can be provided.

[0031] In the second reference example, a p-type or n-type semiconductor layer is provided between the third semiconductor portion 23 and the second electrode portion 52b. The electric field is also relaxed in the second reference example. However, p-type or n-type impurities contained in this semiconductor layer may diffuse into other regions, destabilizing the properties.

[0032] In contrast, in this embodiment, the third semiconductor layer 30 between the third semiconductor portion 23 and the second electrode portion 52b does not need to contain p-type or n-type impurities. This suppresses the destabilization of properties caused by the diffusion of impurities.

[0033] For example, in this embodiment, the concentration of Mg in the third semiconductor layer 30 is 1 × 10⁻⁶. 17 cm -3 The following applies: The Si concentration in the third semiconductor layer 30 is 1 × 10⁻⁶. 17 cm -3 The following is correct. Mg functions as a p-type impurity. Si functions as an n-type impurity.

[0034] In this embodiment, the composition ratio of Al changes in the third semiconductor layer 30. This generates, for example, an electric charge. The generation of the charge is thought to be based on, for example, polarization. Polarization is based on the change in composition ratio. The charge is generated at the location where the composition ratio changes and may be fixed at that location. The charge is, for example, a hole.

[0035] Figure 3 is a schematic diagram illustrating a semiconductor device according to the first embodiment. Figure 3 illustrates the concentration profile of Al in semiconductor material 10M. The horizontal axis of Figure 3 represents the position pZ in the Z-axis direction. The vertical axis represents the Al composition ratio C(Al).

[0036] As shown in Figure 3, the composition ratio C(Al) is low in the first semiconductor layer 10. The composition ratio C(Al) in the second semiconductor layer 20 is higher than that of the first semiconductor layer 10. In the third semiconductor layer 30, the composition ratio C(Al) in the first portion 31 is higher than that of the second portion 32.

[0037] In this example, the Al composition ratio C(Al) in the third semiconductor layer 30 decreases along the direction from the third semiconductor portion 23 to at least a portion of the second electrode portion 52b. The third semiconductor layer 30 is a composition gradient layer.

[0038] In this example, the Al composition ratio y1 in the first part 31 is greater than or equal to the Al composition ratio x2 in the second semiconductor layer 20. The composition ratio y1 may be higher than the composition ratio x2. For example, more charge can be obtained in the third semiconductor layer 30.

[0039] In this embodiment, the thickness t30 of the third semiconductor layer 30 in the second direction D2 (see Figure 3) is, for example, 100 nm to 400 nm. The thickness t31 of the first portion 31 in the second direction D2 may be, for example, 1 nm to 10 nm. The thickness t32 of the second portion 32 in the second direction D2 may be, for example, 1 nm to 10 nm.

[0040] In the embodiment, the thickness t10 of the first semiconductor layer 10 in the second direction D2 may be, for example, 100 nm or more and 2000 nm or less. The thickness t20 of the second semiconductor layer 20 in the second direction D2 may be, for example, 10 nm or more and 100 nm or less.

[0041] As shown in Figures 1 and 3, the third semiconductor layer 30 may further include a third portion 33. The third portion 33 is provided between the first portion 31 and the second portion 32. The third portion 33 is made of Al y3 Ga1-y3 It includes N(0 < y3 < 1, y2 < y3 < y1).

[0042] As shown in FIG. 1, the semiconductor device 110 may further include a substrate 18s and a nitride layer 18b. The substrate 18s may be, for example, a silicon substrate. The nitride layer 18b contains Al, Ga, and N. The nitride layer 18b includes, for example, an AlGaN layer. The nitride layer 18b is provided between the substrate 18s and the semiconductor member 10M. The nitride layer 18b is, for example, a buffer layer.

[0043] As shown in FIG. 1, in this example, the semiconductor device 110 further includes an intermediate nitride layer 17. The intermediate nitride layer 17 is provided between the nitride layer 18b and the first semiconductor layer 10. The intermediate nitride layer 17 contains Ga and N. The intermediate nitride layer 17 contains carbon. The concentration of carbon in the intermediate nitride layer 17 is higher than the concentration of carbon in the first semiconductor layer 10. For example, the first semiconductor layer 10 does not contain carbon. The intermediate nitride layer 17 makes it easier to obtain, for example, high crystallinity. The intermediate nitride layer 17 makes it easier to obtain, for example, high breakdown voltage.

[0044] In this example, the third electrode 53 includes a third electrode portion 53c and a fourth electrode portion 53d. The fourth electrode portion 53d is connected to the third electrode portion 53c. The position of the fourth electrode portion 53d in the first direction D1 is between the position of the third electrode portion 53c in the first direction D1 and the position of the second electrode portion 52b in the first direction D1. The position of at least a part of the third electrode portion 53c in the second direction D2 is between the position of the first semiconductor layer 10 in the second direction D2 and the position of the fourth electrode portion 53d in the second direction D2. The fourth electrode portion 53d is, for example, a flap portion.

[0045] In this example, the first electrode 51 includes a fifth electrode portion 51e and a sixth electrode portion 51f. The sixth electrode portion 51f is connected to the fifth electrode portion 51e. The position of the sixth electrode portion 51f in a first direction D1 is between the position of the fifth electrode portion 51e in a first direction D1 and the position of the third electrode 53 in a first direction D1. The position of at least a portion of the fifth electrode portion 51e in a second direction D2 is between the position of the first semiconductor layer 10 in a second direction D2 and the position of the sixth electrode portion 51f in a second direction D2. The sixth electrode portion 51f is, for example, a eaves portion.

[0046] As shown in Figure 2, the first electrode 51, the second electrode 52, and the third electrode 53 may extend along a third direction D3. The third direction D3 intersects the plane containing the first direction D1 and the second direction D2. The third direction D3 is, for example, the Y-axis direction.

[0047] For example, the first electrode portion 52a, the second electrode portion 52b, the third electrode portion 53c, the fourth electrode portion 53d, the fifth electrode portion 51e, and the sixth electrode portion 51f may extend along the third direction D3.

[0048] As shown in Figure 1, the semiconductor device 110 may further include a first insulating member 41. In this example, the first insulating member 41 includes a first insulating film 41a and a second insulating film 41b. The first insulating film 41a is located between the second semiconductor layer 20 and the second insulating film 41b. In one example, the first insulating film 41a contains silicon and nitrogen. The first insulating film 41a protects, for example, the second semiconductor layer 20. In one example, the second insulating film 41b contains silicon and oxygen. The second insulating film 41b prevents the intrusion of, for example, external impurities (such as water).

[0049] As shown in Figure 1, in this example, at least a portion of the first insulating member 41 (for example, the first insulating film 41a) is provided between the third partial region 13 and the third electrode 53. At least a portion of the first insulating member 41 functions, for example, as a gate insulating film.

[0050] The following describes some examples of the composition ratio of Al in the third semiconductor layer 30.

[0051] Figure 4 is a schematic diagram illustrating a semiconductor device according to the first embodiment. The horizontal axis of Figure 4 represents the position pZ in the Z-axis direction. The vertical axis represents the composition ratio C(Al) of Al. As shown in Figure 4, in the semiconductor device 110a according to the embodiment, the third semiconductor layer 30 includes a first portion 31, a second portion 32, and a third portion 33. The thickness t33 of the third portion 33 in the second direction D2 may be, for example, 1 nm or more and 10 nm or less. Except as described above, the configuration of the semiconductor device 110a may be the same as that of the semiconductor device 110.

[0052] Figure 5 is a schematic diagram illustrating a semiconductor device according to the first embodiment. The horizontal axis in Figure 5 represents the position pZ in the Z-axis direction. The vertical axis represents the composition ratio C(Al) of Al. As shown in Figure 5, in the semiconductor device 110b according to the embodiment, the third semiconductor layer 30 includes a plurality of portions 30p. The first portion 31, the second portion 32, and the third portion 33, etc., may be parts of the plurality of portions 30p. Except for the above, the configuration of the semiconductor device 110b may be the same as the configuration of the semiconductor device 110.

[0053] Multiple portions 30p are aligned along the second direction D2 (Z-axis direction). The composition ratio of Al in the multiple portions 30p is substantially constant. The thickness t30p of each of the multiple portions 30p in the second direction is 10 nm or less. The thickness t30p may be 1 nm or more.

[0054] In the examples of semiconductor devices 110, 110a, and 110b, charges (e.g., holes) are generated at positions in the Z-axis direction where the Al composition ratio C(Al) changes. A short distance between multiple positions where the composition ratio C(Al) changes results in a higher concentration of generated charges (holes). This makes it easier for carriers trapped in the trap to move, or for the trapped carriers to be neutralized. This more effectively suppresses the accumulation of carriers during operation and the resulting fluctuations in characteristics.

[0055] For example, by having a thickness t30p of 10 nm or less in the second direction of each of the multiple portions 30p, the distance between the multiple locations where the composition ratio C(Al) changes is effectively shortened. This allows for more effective suppression of variations in properties.

[0056] Figure 6 is a schematic diagram illustrating a semiconductor device according to the first embodiment. In Figure 6, the horizontal axis represents the position pZ in the Z-axis direction. The vertical axis represents the Al composition ratio C(Al). As shown in Figure 6, in the semiconductor device 110c according to the embodiment, the Al composition ratio C(Al) in the third semiconductor layer 30 changes continuously. Except for the above, the configuration of the semiconductor device 110c may be the same as that of the semiconductor device 110. In the semiconductor device 110c, the Al composition ratio C(Al) decreases monotonically along the direction from the third semiconductor portion 23 to at least a part of the second electrode portion 52b. The Al composition ratio C(Al) may change linearly or curvilinearly. Even in the semiconductor device 110c, a semiconductor device with stabilized characteristics can be provided.

[0057] Figures 7 and 8 are schematic cross-sectional views illustrating a semiconductor device according to the first embodiment. Figures 7 and 8 are cross-sectional views corresponding to the section along line A1-A2 in Figure 2.

[0058] As shown in Figure 7, in the semiconductor device 111 according to the embodiment, at least a portion of the first insulating member 41 is located between the third semiconductor layer 30 and the second electrode portion 52b in the second direction D2. The configuration of the semiconductor device 111, excluding this, may be the same as that of the semiconductor device 110 (and semiconductor devices 110a to 110c). In the semiconductor device 111, at least a portion of the first insulating film 41a is provided between a portion of the third semiconductor layer 30 and the second electrode portion 52b in the second direction D2.

[0059] As shown in Figure 8, in the semiconductor device 111a according to the embodiment, at least a portion of the first insulating member 41 is located between the third semiconductor layer 30 and the second electrode portion 52b in the second direction D2. The configuration of the semiconductor device 111a, excluding this, may be the same as that of the semiconductor device 110 (and semiconductor devices 110a to 110c). In the semiconductor device 111a, at least a portion of the first insulating film 41a is provided between the entire third semiconductor layer 30 and the second electrode portion 52b in the second direction D2. By having at least a portion of the first insulating film 41a cover the entire third semiconductor layer 30 in the second direction D2, it becomes easier to maintain a high concentration of charge (e.g., holes).

[0060] Figures 9(a) to 9(c) are schematic diagrams illustrating a semiconductor device according to the first embodiment. Figure 9(a) is a plan view. Figure 9(b) is a cross-sectional view taken along the line Y1-Y2 in Figure 9(a). Figure 9(c) is a cross-sectional view taken along the line Y3-Y4 in Figure 9(a).

[0061] As shown in Figure 9(a), in the semiconductor device 112 according to the embodiment, the semiconductor member 10M includes a plurality of the third semiconductor layers 30. The configuration of the semiconductor device 112 other than this may be the same as the configuration of the semiconductor device 110 (and semiconductor devices 110a to 110c).

[0062] Multiple third semiconductor layers 30 are aligned, for example, along a third direction D3 (for example, the Y-axis direction). The third direction D3 intersects a plane containing the first direction D1 and the second direction D2. The direction from one of the multiple third semiconductor layers 30 to another of the multiple third semiconductor layers 30 is along the third direction D3.

[0063] As shown in Figure 9(b), each of the multiple third semiconductor layers 30 is provided between the third semiconductor portion 23 and the second electrode portion 52b in the second direction D2.

[0064] As shown in Figure 9(a), at least a portion of the first insulating member 41 is located between one of the plurality of third semiconductor layers 30 and another of the plurality of third semiconductor layers 30 in the third direction. As shown in Figure 9(c), at least a portion of the first insulating member 41 is provided between the third semiconductor portion 23 and the second electrode portion 52b.

[0065] In the semiconductor device 112, the island-shaped third semiconductor layer 30 and a part of the first insulating member 41 are arranged alternately in the third direction D3.

[0066] For example, by providing a third semiconductor layer 30 that includes a second portion 32 with a low Al composition ratio, it becomes difficult for carrier regions 10c (two-dimensional electron gas) to form. If the third semiconductor layer 30 is in the shape of a strip extending along the third direction D3, the on-resistance may increase excessively. For example, by providing multiple island-shaped third semiconductor layers 30, the carrier regions 10c can be formed appropriately, and an excessive increase in on-resistance can be suppressed.

[0067] Figures 10(a) to 10(c) are schematic diagrams illustrating a semiconductor device according to the first embodiment. Figure 10(a) is a plan view. Figure 10(b) is a cross-sectional view taken along the line Y1-Y2 in Figure 10(a). Figure 10(c) is a cross-sectional view taken along the line Y3-Y4 in Figure 10(a).

[0068] As shown in Figure 10(a), in the semiconductor device 112a according to this embodiment, the semiconductor member 10M also includes a plurality of the third semiconductor layers 30. The configuration of the semiconductor device 112a, excluding this, may be the same as the configuration of the semiconductor device 112.

[0069] As shown in Figure 10(a), in the semiconductor device 112a, the length of one of the multiple third semiconductor layers 30 in the first direction D1 is longer than the length of one of the multiple third semiconductor layers 30 in the third direction D3. Each of the multiple third semiconductor layers 30 may be striped. A portion of each of the multiple third semiconductor layers 30 does not need to overlap with the second electrode portion 52b in the second direction D2.

[0070] Figure 11 is a schematic cross-sectional view illustrating a semiconductor device according to the first embodiment. As shown in Figure 11, the semiconductor device 113 according to the embodiment further includes a first conductive member 61. The configuration of the semiconductor device 113, excluding the first conductive member, may be the same as that of semiconductor devices 110, 110a to 110c, 111, 111a, 112, and 112a.

[0071] The first conductive member 61 is electrically connected to the first electrode 51. In this example, the first conductive member 61 is electrically connected to the first electrode 51 by a connecting member 61L. The position of the first conductive member 61 in the first direction D1 is between the position of the third electrode 53 in the first direction D1 and the position of the second electrode 52 in the first direction D1. For example, the first conductive member 61 functions as a source field plate. By providing the first conductive member 61, the electric field is mitigated, making it easier to obtain high withstand voltage.

[0072] The semiconductor device 113 may further include a second conductive member 62. The second conductive member 62 is electrically connected to the first electrode 51. For example, at least a portion of the third electrode 53 is provided between the semiconductor member 10M and the second conductive member 62 in the second direction D2. The second conductive member 62 functions as a source field plate. The provision of the second conductive member 62 mitigates the electric field, making it easier to obtain a high withstand voltage.

[0073] The semiconductor device 113 may further include a third conductive member 63. The third conductive member 63 is electrically connected to the second electrode 52. The second electrode portion 52b is provided between the semiconductor member 10M and the third conductive member 63 in the second direction D2. The semiconductor device 113 may further include a second insulating member 42. At least a portion of the second insulating member 42 is provided between the second electrode portion 52b and the third conductive member 63 in the second direction D2. The third conductive member 63 functions, for example, as a drain wire. The provision of the third conductive member 63 reduces resistance, making it easier to obtain a low on-resistance.

[0074] The second insulating member 42 includes, for example, a third insulating film 42c and a fourth insulating film 42d. The third insulating film 42c is located between the first insulating member 41 and the fourth insulating film 42d. In one example, the third insulating film 42c and the fourth insulating film 42d include silicon and oxygen.

[0075] Figure 12 is a schematic cross-sectional view illustrating a semiconductor device according to the first embodiment. As shown in Figure 12, the semiconductor device 114 according to this embodiment further includes a first conductive member 61. The configuration of the semiconductor device 114, excluding the first conductive member 61, may be the same as that of the semiconductor device 113.

[0076] A portion of the third semiconductor layer 30 is provided between the second semiconductor portion 22 and the first conductive member 61. The Al composition ratio in the above portion of the third semiconductor layer 30 decreases along the direction from the second semiconductor layer 20 to the first conductive member 61. At least a portion of the first insulating member 41 may be provided between the above portion of the third semiconductor layer 30 and the first conductive member 61.

[0077] For example, the first conductive member 61 functions as a source field plate. A third semiconductor layer 30 with a changing Al composition ratio is provided between the second semiconductor portion 22 and the first conductive member 61. This allows for the mitigation of the electric field while suppressing fluctuations in characteristics.

[0078] Figure 13 is a schematic cross-sectional view illustrating a semiconductor device according to the first embodiment. As shown in Figure 13, in the semiconductor device 115 according to this embodiment, a portion of the third semiconductor layer 30 is provided between the second semiconductor layer 20 and the fourth electrode portion 53d. The configuration of the semiconductor device 115, excluding this portion, may be the same as that of the semiconductor device 113.

[0079] In the semiconductor device 115, the third electrode 53 includes a third electrode portion 53c and a fourth electrode portion 53d. The fourth electrode portion 53d is connected to the third electrode portion 53c. The position of the fourth electrode portion 53d in a first direction D1 is between the position of the third electrode portion 53c in a first direction D1 and the position of the second electrode portion 52b in a first direction D1. A portion of the third semiconductor layer 30 is provided between the second semiconductor portion 22 and the fourth electrode portion 53d. The composition ratio of Al in the above portion of the third semiconductor layer 30 decreases along the direction from the second semiconductor portion 22 to the fourth electrode portion 53d. At least a portion of the first insulating member 41 may be provided between the above portion of the third semiconductor layer 30 and the fourth electrode portion 53d.

[0080] In the semiconductor device 115, the electric field at the position overlapping with the fourth electrode portion 53d is relaxed, making it easier to obtain a high breakdown voltage. By providing a portion of the third semiconductor layer 30, in which the Al composition ratio changes, between the second semiconductor portion 22 and the fourth electrode portion 53d, for example, an increase in on-resistance during operation is suppressed.

[0081] Figure 14 is a schematic cross-sectional view illustrating a semiconductor device according to the first embodiment. As shown in Figure 14, in the semiconductor device 116 according to this embodiment, at least a portion of the third electrode 53 is provided between the first semiconductor portion 21 and the second semiconductor portion 22 in the first direction. The configuration of the semiconductor device 116, excluding this, may be the same as that of the semiconductor device 115.

[0082] In semiconductor device 116, the third electrode 53 is, for example, a recessed gate electrode. This makes it easier to obtain a high threshold voltage. For example, normally-off operation can be achieved.

[0083] At least a portion of the third electrode 53 may be provided between the fourth partial region 14 and the fifth partial region 15 in the first direction. As shown in Figure 14, at least a portion of the first insulating member 41 may be provided between the first semiconductor layer 10 and the third electrode 53, and between the second semiconductor layer 20 and the third electrode 53.

[0084] In the semiconductor device 116, the third semiconductor layer 30 provided between the second semiconductor portion 22 and the fourth electrode portion 53d may be omitted.

[0085] (Second Embodiment) The second embodiment relates to a method for manufacturing a semiconductor device. Figs. 15(a) to 15(c) are schematic cross-sectional views illustrating a method for manufacturing a semiconductor device according to the second embodiment. As shown in Fig. 15(a), a third semiconductor layer 30 is formed on the second semiconductor layer 20 provided on the first semiconductor layer 10. The first semiconductor layer 10 is Al x1 Ga 1-x1 N (0 ≦ x1 < 1). The second semiconductor layer 20 is Al x2 Ga 1-x2 N (0 < x2 < 1, x1 < x2). The third semiconductor layer 30 contains Al, Ga, and N. The third semiconductor layer 30 includes a first portion 31 containing Al y1 Ga 1-y1 N (0 < y1 ≦ 1) and a second portion 32 containing Al y2 Ga 1-y2 N (0 ≦ y2 < 1, y2 < y1). The first portion 31 is between the second semiconductor layer 20 and the second portion 32.

[0086] The second direction D2 from the first semiconductor layer 10 to the second semiconductor layer 20 is along the Z-axis direction. The composition ratio of Al in the third semiconductor layer 30 may decrease in the Z-axis direction in a direction away from the second semiconductor layer 20. The third semiconductor layer 30 may be, for example, a composition gradient layer in which the composition ratio of Al changes.

[0087] As shown in Fig. 15(b), a part of the third semiconductor layer 30 is removed to expose a part of the second semiconductor layer 20.

[0088] As shown in FIG. 15(c), an electrode (for example, the second electrode 52) is formed on at least a part of the above-mentioned part of the exposed second semiconductor layer 20 and on the remaining third semiconductor layer 30. The electrode formed on at least a part of the above-mentioned part of the exposed second semiconductor layer 20 corresponds to the first electrode portion 52a. The electrode formed on the remaining third semiconductor layer 30 corresponds to the second electrode portion 52b. A method of manufacturing a semiconductor device capable of stabilizing characteristics can be provided.

[0089] FIGS. 16(a) and 16(b) are schematic cross-sectional views illustrating a method of manufacturing a semiconductor device according to the second embodiment. As shown in FIG. 16(a), a third semiconductor layer 30 is formed on a part of the second semiconductor layer 20 provided on the first semiconductor layer 10. The first semiconductor layer 10 is Al x1 Ga 1-x1 N (0 ≦ x1 < 1). The second semiconductor layer 20 is Al x2 Ga 1-x2 N (0 < x2 < 1, x1 < x2). The third semiconductor layer 30 contains Al, Ga, and N. The third semiconductor layer 30 is Al y1 Ga 1-y1 N (0 < y1 ≦ 1) and a second portion 32 containing Al y2 Ga 1-y2 N (0 ≦ y2 < 1, y2 < y1). The first portion 31 is between the second semiconductor layer 20 and the second portion 32.

[0090] For example, a mask including an opening is formed on the second semiconductor layer 20. In the opening, the third semiconductor layer 30 is formed on the second semiconductor layer 20. The third semiconductor layer 30 is formed on a part of the second semiconductor layer 20.

[0091] The second direction D2 from the first semiconductor layer 10 to the second semiconductor layer 20 is along the Z-axis direction. The composition ratio of Al in the third semiconductor layer 30 may decrease in the direction away from the second semiconductor layer 20 in the Z-axis direction. The third semiconductor layer 30 may be, for example, a composition gradient layer in which the composition ratio of Al changes.

[0092] As shown in Figure 16(b), electrodes (e.g., second electrode 52) are formed on the other part of the second semiconductor layer 20 and on the third semiconductor layer 30. The electrode formed on the other part of the second semiconductor layer 20 corresponds to the first electrode portion 52a. The electrode formed on the third semiconductor layer 30 corresponds to the second electrode portion 52b. A method for manufacturing a semiconductor device that can stabilize its characteristics can be provided.

[0093] Information regarding length and thickness can be obtained through electron microscopy observations, etc. Information regarding the material composition can be obtained through SIMS (Secondary Ion Mass Spectrometry) or EDX (Energy dispersive X-ray spectroscopy), etc.

[0094] The embodiments may include the following technical proposals. (Technical proposal 1) First electrode and, A second electrode, wherein the direction from the first electrode to the second electrode is along the first direction, and the second electrode includes a first electrode portion and a second electrode portion, the second electrode portion being connected to the first electrode portion, A third electrode, wherein the position of the third electrode in the first direction is between the position of the first electrode in the first direction and the position of the second electrode in the first direction. Semiconductor components and Equipped with, The aforementioned semiconductor member is Al x1 Ga 1-x1A first semiconductor layer containing N(0≦x1<1), wherein the first semiconductor layer includes a first partial region, a second partial region, a third partial region, a fourth partial region, a fifth partial region, and a sixth partial region, the second direction from the first partial region to the first electrode intersects the first direction, the direction from the second partial region to the first electrode portion is along the second direction, the direction from the sixth partial region to the second electrode portion is along the second direction, the direction from the third partial region to the third electrode is along the second direction, the position of the fourth partial region in the first direction is between the position of the first partial region in the first direction and the position of the third partial region in the first direction, the position of the fifth partial region in the first direction is between the position of the third partial region in the first direction and the position of the second partial region in the first direction, the position of the sixth partial region in the first direction is between the position of the fifth partial region in the first direction and the position of the second partial region in the first direction, the first semiconductor layer; Al x2 Ga 1-x2 A second semiconductor layer containing N(0<x2<1, x1<x2), wherein the second semiconductor layer includes a first semiconductor part, a second semiconductor part, and a third semiconductor part, the direction from the fourth partial region to the first semiconductor part is along the second direction, the direction from the fifth partial region to the second semiconductor part is along the second direction, the direction from the sixth partial region to the third semiconductor part is along the second direction, the second semiconductor layer; A third semiconductor layer containing Al, Ga, and N, at least a part of the third semiconductor layer is provided between the third semiconductor part and at least a part of the second electrode part in the second direction, the third semiconductor layer is Al y1 Ga 1-y1 A first part containing N(0<y1≦1), Al y2 Ga 1-y2 A second part containing N(0≦y2<1, y2<y1), the second part is between the first part and at least a part of the second electrode part, the third semiconductor layer; A semiconductor device including.

[0095] (Technical Solution 2) The semiconductor device according to Technical Solution 1, wherein y1 is not less than x2.

[0096] (Technical Solution 3) The semiconductor device according to Technical Solution 1, wherein y1 is higher than x2.

[0097] (Technical Solution 4) The third semiconductor layer further includes a third portion provided between the first portion and the second portion, The third portion is Al y3 Ga 1-y3 N (0 < y3 < 1, y2 < y3 < y1), and the semiconductor device according to any one of Technical Solutions 1 to 3.

[0098] (Technical Solution 5) The semiconductor device according to any one of Technical Solutions 1 to 4, wherein the composition ratio of Al in the third semiconductor layer decreases along the direction from the third semiconductor portion to at least a part of the second electrode portion.

[0099] (Technical Solution 6) The third semiconductor layer includes a plurality of portions arranged along the second direction, The composition ratio of Al in the plurality of portions is substantially constant, The thickness of each of the plurality of portions in the second direction is 10 nm or less, and the semiconductor device according to Technical Solution 5.

[0100] (Technical Solution 7) The concentration of Mg in the third semiconductor layer is 1×10 17 cm -3 or less, and the semiconductor device according to any one of Technical Solutions 1 to 6.

[0101] (Technical Solution 8) The thickness of the third semiconductor layer in the second direction is 100 nm or more and 400 nm or less, and the semiconductor device according to any one of Technical Solutions 1 to 7.

[0102] (Technical Solution 9) Further comprising a first insulating member, A semiconductor device according to any one of the technical proposals 1 to 8, wherein at least a portion of the first insulating member is located between the third semiconductor layer and the second electrode portion in the second direction.

[0103] (Technical proposal 10) Further comprising a first insulating member, The semiconductor member includes a plurality of the third semiconductor layers, The direction from one of the plurality of third semiconductor layers to another of the plurality of third semiconductor layers is along a third direction that intersects a plane including the first direction and the second direction. At least a portion of the first insulating member is located between one of the plurality of third semiconductor layers and another of the plurality of third semiconductor layers in the third direction. The semiconductor device according to any one of Technical Proposals 1 to 8, wherein at least a portion of the first insulating member is provided between the third semiconductor portion and the second electrode portion.

[0104] (Technical proposal 11) The first conductive member is further electrically connected to the first electrode, The position of the first conductive member in the first direction is between the position of the third electrode in the first direction and the position of the second electrode in the first direction. A portion of the third semiconductor layer is provided between the second semiconductor portion and the first conductive member. The semiconductor device according to any one of Technical Proposals 1 to 8, wherein the composition ratio of Al in the portion of the third semiconductor layer decreases along the direction from the second semiconductor layer to the first conductive member.

[0105] (Technical proposal 12) The third electrode includes a third electrode portion and a fourth electrode portion, The aforementioned fourth electrode portion is connected to the aforementioned third electrode portion. The position of the fourth electrode portion in the first direction is between the position of the third electrode portion in the first direction and the position of the second electrode portion in the first direction. A portion of the third semiconductor layer is provided between the second semiconductor portion and the fourth electrode portion. The semiconductor device according to any one of Technical Proposals 1 to 8, wherein the composition ratio of Al in the portion of the third semiconductor layer decreases along the direction from the second semiconductor portion to the fourth electrode portion.

[0106] (Technical proposal 13) Further comprising a first insulating member, At least a portion of the third electrode is provided between the first semiconductor portion and the second semiconductor portion in the first direction. The semiconductor device according to Technical Proposal 12, wherein at least a portion of the first insulating member is provided between the first semiconductor layer and the third electrode, and between the second semiconductor layer and the third electrode.

[0107] (Technical proposal 14) Further comprising a first insulating member, At least a portion of the third electrode is provided between the first semiconductor portion and the second semiconductor portion in the first direction. A semiconductor device according to any one of Technical Proposals 1 to 8, wherein at least a portion of the first insulating member is provided between the first semiconductor layer and the third electrode, and between the second semiconductor layer and the third electrode.

[0108] (Technical proposal 15) The device further comprises a second conductive member electrically connected to the first electrode, A semiconductor device according to any one of Technical Proposals 1 to 14, wherein at least a portion of the third electrode is provided between the semiconductor member and the second conductive member in the second direction.

[0109] (Technical proposal 16) A third conductive member electrically connected to the second electrode, The second insulating member, The second electrode portion is provided between the semiconductor member and the third conductive member in the second direction, At least a part of the second insulating member is provided between the second electrode portion and the third conductive member in the second direction, according to any one of the semiconductor devices described in Technical Solutions 1 to 15.

[0110] (Technical Solution 17) The second electrode portion extends along a third direction intersecting a plane including the first direction and the second direction, according to any one of the semiconductor devices described in Technical Solutions 1 to 9.

[0111] (Technical Solution 18) x1 is 0 or more and less than 0.15, x2 is 0.15 or more and 0.4 or less, y1 is 0.15 or more and 0.8 or less, y2 is 0 or more and less than 0.15, according to any one of the semiconductor devices described in Technical Solutions 1 to 17.

[0112] (Technical Solution 19) Al x1 Ga 1-x1 Provided on a first semiconductor layer containing Al, Ga, N (0≦x1<1), x2 Ga 1-x2 Form a third semiconductor layer containing Al, Ga, and N on a second semiconductor layer containing N (0<x2<1, x1<x2). The third semiconductor layer contains Al, y1 Ga 1-y1 A first portion containing N (0<y1≦1), and Al, y2 Ga 1-y2 A second portion containing N (0≦y2<1, y2<y1), and the first portion is between the second semiconductor layer and the second portion, Remove a part of the third semiconductor layer to expose a part of the second semiconductor layer, Form an electrode on at least a part of the exposed part of the second semiconductor layer and on the remaining third semiconductor layer, a method for manufacturing a semiconductor device.

[0113] (Technical Solution 20) Al x1 Ga 1-x1 Provided on a first semiconductor layer containing Al, Ga, N (0≦x1<1),x2 Ga 1-x2 Form a third semiconductor layer containing Al, Ga, and N on a part of a second semiconductor layer containing N(0 < x2 < 1, x1 < x2). The third semiconductor layer contains Al y1 Ga 1-y1 A first part containing N(0 < y1 ≦ 1), Al y2 Ga 1-y2 A second part containing N(0 ≦ y2 < 1, y2 < y1), and the first part is between the part of the second semiconductor layer and the second part, A method of manufacturing a semiconductor device, comprising forming electrodes on another part of the second semiconductor layer and on the third semiconductor layer.

[0114] According to an embodiment, a semiconductor device and a method for manufacturing the same capable of stabilizing characteristics are provided.

[0115] The embodiments of the present invention have been described above with reference to examples. However, the present invention is not limited to these examples. For example, regarding the specific configurations of each element such as electrodes, semiconductor regions, and insulating members included in the semiconductor device, the present invention can be similarly implemented by appropriately selecting from the range known to those skilled in the art, and as long as the same effects can be obtained, it is included in the scope of the present invention.

[0116] Combinations of any two or more elements of each example are also included in the scope of the present invention as long as they include the gist of the present invention within the technically possible range.

[0117] Based on the semiconductor device and the method for manufacturing the same described above as embodiments of the present invention, all semiconductor devices and the methods for manufacturing the same that can be appropriately designed and modified by those skilled in the art also belong to the scope of the present invention as long as they include the gist of the present invention.

[0118] Those skilled in the art can conceive various modification examples and correction examples within the scope of the idea of the present invention, and it is understood that those modification examples and correction examples also belong to the scope of the present invention.

[0119] While several embodiments of the present invention have been described, these embodiments are presented as examples only and are not intended to limit the scope of the invention. These novel embodiments can be carried out in a variety of other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their variations are included in the scope and spirit of the invention, as well as in the claims of the invention and its equivalents. [Explanation of symbols]

[0120] 10, 20, 30: 1st, 2nd, and 3rd semiconductor layers, 10M: semiconductor material, 10c: carrier region, 11-16: 1st to 6th partial regions, 17: intermediate nitride layer, 18b: nitride layer, 18s: substrate, 21-23: 1st to 3rd semiconductor portions, 30p: portion, 31-33: 1st to 3rd portions, 41, 42: 1st and 2nd insulating materials, 41a, 41b: 1st and 2nd insulating films, 42c, 42d: 3rd and 4th insulating films, 51-53: 1st to 3rd electrodes, 51e, 52f: 5th and 6th electrode portions, 52a, 52b: 1st and 2nd electrode portions, 53c, 53d: 3rd and 4th electrode portions, 61-63: 1st to 3rd conductive materials, 61L: Connecting member, 110, 110a~110c, 111, 111a, 112, 112a, 113~116: Semiconductor device, C(Al): Composition ratio, D1~D3: 1st to 3rd direction, t10, t20, t30, t30p, t31~t33: Thickness

Claims

1. First electrode and A second electrode, wherein the direction from the first electrode to the second electrode is along the first direction, and the second electrode includes a first electrode portion and a second electrode portion, the second electrode portion being connected to the first electrode portion, A third electrode, wherein the position of the third electrode in the first direction is between the position of the first electrode in the first direction and the position of the second electrode in the first direction. Semiconductor components and Equipped with, The aforementioned semiconductor member is Al ｘ１ Ga １－ｘ１ A first semiconductor layer comprising N (0 ≤ x1 < 1), wherein the first semiconductor layer includes a first subregion, a second subregion, a third subregion, a fourth subregion, a fifth subregion, and a sixth subregion, the second direction from the first subregion to the first electrode intersects the first direction, the direction from the second subregion to the first electrode portion follows the second direction, the direction from the sixth subregion to the second electrode portion follows the second direction, the direction from the third subregion to the third electrode follows the second direction, the position of the fourth subregion in the first direction is between the position of the first subregion in the first direction and the position of the third subregion in the first direction, the position of the fifth subregion in the first direction is between the position of the third subregion in the first direction and the position of the second subregion in the first direction, and the position of the sixth subregion in the first direction is between the position of the fifth subregion in the first direction and the position of the second subregion in the first direction. Al ｘ２ Ga １－ｘ２ A second semiconductor layer comprising N (0 < x2 < 1, x1 < x2), wherein the second semiconductor layer includes a first semiconductor portion, a second semiconductor portion, and a third semiconductor portion, and the direction from the fourth partial region to the first semiconductor portion follows the second direction, the direction from the fifth partial region to the second semiconductor portion follows the second direction, and the direction from the sixth partial region to the third semiconductor portion follows the second direction, A third semiconductor layer comprising Al, Ga, and N, wherein at least a portion of the third semiconductor layer is provided between the third semiconductor portion and at least a portion of the second electrode portion in the second direction, and the third semiconductor layer comprises Al ｙ１ Ga １－ｙ１ The first part includes N (0 < y1 ≤ 1), and Al ｙ２ Ga １－ｙ２ A second portion including N (0 ≤ y² < 1, y² < y¹), the third semiconductor layer being located between the first portion and at least a portion of the second electrode portion, A semiconductor device that includes [the above].

2. The semiconductor device according to claim 1, wherein y1 is greater than or equal to x2.

3. The semiconductor device according to claim 1, wherein y1 is higher than x2.

4. The semiconductor device according to any one of claims 1 to 3, wherein the composition ratio of Al in the third semiconductor layer decreases along the direction from the third semiconductor portion to at least a portion of the second electrode portion.

5. The third semiconductor layer includes a plurality of portions aligned along the second direction, The composition ratio of Al in the aforementioned multiple parts is substantially constant. The semiconductor device according to claim 4, wherein the thickness of each of the multiple parts in the second direction is 10 nm or less.

6. Further comprising a first insulating member, The semiconductor member includes a plurality of the third semiconductor layers, The direction from one of the plurality of third semiconductor layers to another of the plurality of third semiconductor layers is along a third direction that intersects a plane including the first direction and the second direction. At least a portion of the first insulating member is located between one of the plurality of third semiconductor layers and another of the plurality of third semiconductor layers in the third direction. The semiconductor device according to claim 1, wherein at least a portion of the first insulating member is provided between the third semiconductor portion and the second electrode portion.

7. The first electrode is further comprising a first conductive member electrically connected to the first electrode, The position of the first conductive member in the first direction is between the position of the third electrode in the first direction and the position of the second electrode in the first direction. A portion of the third semiconductor layer is provided between the second semiconductor portion and the first conductive member. The semiconductor device according to claim 1, wherein the composition ratio of Al in the portion of the third semiconductor layer decreases along the direction from the second semiconductor layer to the first conductive member.

8. The third electrode includes a third electrode portion and a fourth electrode portion. The aforementioned fourth electrode portion is connected to the aforementioned third electrode portion. The position of the fourth electrode portion in the first direction is between the position of the third electrode portion in the first direction and the position of the second electrode portion in the first direction. A portion of the third semiconductor layer is provided between the second semiconductor portion and the fourth electrode portion. The semiconductor device according to claim 1, wherein the composition ratio of Al in the portion of the third semiconductor layer decreases along the direction from the second semiconductor portion to the fourth electrode portion.

9. Al ｘ１ Ga １－ｘ１ Al provided on a first semiconductor layer containing N (0 ≦ x1 < 1) ｘ２ Ga １－ｘ２ Form a third semiconductor layer containing Al, Ga and N on a second semiconductor layer containing N (0 < x2 < 1, x1 < x2), and the third semiconductor layer is Al ｙ１ Ga １－ｙ１ A first portion containing N (0 < y1 ≦ 1), and Al ｙ２ Ga １－ｙ２ A second portion containing N (0 ≦ y2 < 1, y2 < y1), and the first portion is between the second semiconductor layer and the second portion By removing a portion of the third semiconductor layer, a portion of the second semiconductor layer is exposed. A method for manufacturing a semiconductor device, comprising forming electrodes on at least a portion of the exposed second semiconductor layer and on the remaining third semiconductor layer.

10. Al ｘ１ Ga １－ｘ１ Al is provided on a first semiconductor layer containing N (0 ≤ x1 < 1). ｘ２ Ga １－ｘ２ A third semiconductor layer containing Al, Ga, and N is formed on a portion of a second semiconductor layer containing N (0 < x2 < 1, x1 < x2), and the third semiconductor layer is Al ｙ１ Ga １－ｙ１ The first part includes N (0 < y1 ≤ 1), and Al ｙ２ Ga １－ｙ２ A second portion including N (0 ≤ y² < 1, y² < y¹), the first portion being located between the first portion and the second portion of the second semiconductor layer, A method for manufacturing a semiconductor device, comprising forming electrodes on another portion of the second semiconductor layer and on the third semiconductor layer.

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