Semiconductor Device

Abstract

To provide a semiconductor device capable of improving characteristics thereof.SOLUTION: According to one embodiment, a semiconductor device includes first to third electrodes, first and second semiconductor layers, and a first compound member. The first semiconductor layer contains Alx1Ga1-x1N (0≤x1<1). The second semiconductor layer contains Alx2Ga1-x2N (0<x2<1 and x1<x2). The first compound member contains Aly1Ga1-y1N (0<y1≤1 and x2<y1). A plurality of first compound portions in the first compound member are between the first semiconductor layer and the first electrode. A portion of the first electrode is between one of the plurality of first compound portions and other one of the plurality of first compound portions.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] FIELD An embodiment of the present invention relates to a semiconductor device. [Background technology]

[0002] For example, there are semiconductor devices such as transistors using nitride semiconductors, and it is desirable to improve the characteristics of such semiconductor devices. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2013-229486 A Summary of the Invention [Problem to be solved by the invention]

[0004] An embodiment of the present invention provides a semiconductor device capable of improving characteristics. [Means for solving the problem]

[0005] According to an embodiment of the present invention, a semiconductor device includes a first electrode, a second electrode, a third electrode, a first semiconductor layer, a second semiconductor layer, and a first compound member. The position of the third electrode in a first direction from the second electrode to the first electrode is between the position of the second electrode in the first direction and the position of the first electrode in the first direction. The first semiconductor layer is made of 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, and a fifth 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 second electrode is along the second direction. The direction from the third partial region to the third electrode is along the second direction. The fourth partial region is between the third partial region and the first partial region in the first direction. The fifth partial region is between the second partial region and the third partial region in the first direction. The second semiconductor layer includes Al x2 Ga 1-x2 It includes N(0<x2<1, x1<x2). The second semiconductor layer includes a first semiconductor region, a second semiconductor region, and a third semiconductor region. The direction from the fourth partial region to the first semiconductor region is along the second direction. The direction from the fifth partial region to the second semiconductor region is along the second direction. The third semiconductor region is between the first partial region and the first electrode in the second direction. The first compound member includes Al y1 Ga 1-y1 It includes N(0<y1≦1, x2<y1). The first compound member includes a plurality of first compound parts. The plurality of first compound parts are between the third semiconductor region and the first electrode. A part of the first electrode is between one of the plurality of first compound parts and another one of the plurality of first compound parts.

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. [Diagram 2] FIGS. 2(a) to 2(c) are schematic plan views illustrating a semiconductor device according to the first embodiment. [Diagram 3] FIG. 3 is a schematic cross-sectional view illustrating a semiconductor device according to the second embodiment. [Figure 4] FIG. 4 is a schematic cross-sectional view illustrating a semiconductor device according to the second embodiment. [Diagram 5] FIG. 5 is a schematic cross-sectional view illustrating a semiconductor device according to the second embodiment. [Figure 6] FIG. 6 is a schematic cross-sectional view illustrating the semiconductor device according to the third embodiment. [Figure 7] FIG. 7 is a schematic cross-sectional view illustrating the semiconductor device according to the embodiment. [Figure 8] FIG. 8 is a schematic cross-sectional view illustrating the semiconductor device according to the embodiment. [Figure 9] FIG. 9 is a schematic cross-sectional view illustrating the semiconductor device according to the embodiment. [Figure 10] FIG. 10 is a schematic cross-sectional view illustrating the semiconductor device according to the embodiment. [Figure 11] FIG. 11 is a schematic cross-sectional view illustrating the semiconductor device according to the embodiment. [Figure 12] FIG. 12 is a schematic cross-sectional view illustrating the semiconductor device according to the embodiment. [Figure 13] FIG. 13 is a schematic cross-sectional view illustrating the semiconductor device according to the embodiment. [Figure 14] FIG. 14 is a schematic cross-sectional view illustrating the semiconductor device according to the embodiment. [Figure 15] FIG. 15 is a schematic cross-sectional view illustrating the semiconductor device according to the embodiment. [Figure 16] FIG. 16 is a schematic cross-sectional view illustrating the semiconductor device according to the embodiment. [Figure 17] FIG. 17 is a schematic cross-sectional view illustrating the semiconductor device according to the embodiment. [Figure 18] FIG. 18 is a schematic cross-sectional view illustrating the semiconductor device according to the embodiment. [Figure 19] FIG. 19 is a schematic cross-sectional view illustrating the semiconductor device according to the embodiment. [Figure 20] FIG. 20 is a schematic cross-sectional view illustrating the semiconductor device according to the embodiment. [Figure 21] FIG. 21 is a schematic cross-sectional view illustrating the semiconductor device according to the embodiment. [Figure 22] FIG. 22 is a schematic cross-sectional view illustrating the semiconductor device according to the embodiment. [Figure 23] FIG. 23 is a schematic cross-sectional view illustrating the semiconductor device according to the embodiment. [Figure 24] FIG. 24 is a schematic cross-sectional view illustrating the semiconductor device according to the embodiment. [Diagram 25] FIG. 25 is a schematic cross-sectional view illustrating the semiconductor device according to the embodiment. [Figure 26] FIG. 26 is a schematic cross-sectional view illustrating the semiconductor device according to the embodiment. [Figure 27] FIG. 27 is a schematic cross-sectional view illustrating the semiconductor device according to the embodiment. [Figure 28] FIG. 28 is a schematic cross-sectional view illustrating the semiconductor device according to the embodiment. [Figure 29] FIG. 29 is a schematic cross-sectional view illustrating a semiconductor device according to the embodiment. [Diagram 30] FIG. 30 is a schematic cross-sectional view illustrating the semiconductor device according to the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[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. Even when the same part is shown, the dimensions and ratios of each part may be different depending on the drawing. In this specification and each drawing, elements similar to those described above with reference to the previous drawings are given 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 first electrode 51, a second electrode 52, a third electrode 53, a first semiconductor layer 11, a second semiconductor layer 12, and a first compound member 31.

[0009] A first direction from the second electrode 52 to the first electrode 51 is defined as the X-axis direction. A direction perpendicular to the X-axis direction is defined as the Z-axis direction. A direction perpendicular to the X-axis direction and the Z-axis direction is defined as the Y-axis direction.

[0010] The position of the third electrode 53 in the first direction (X-axis direction) is between the position of the second electrode 52 in the first direction and the position of the first electrode 51 in the first direction. For example, in the X-axis direction, the third electrode 53 is between the second electrode 52 and the first electrode 51.

[0011] The first semiconductor layer 11 is Al x1 Ga 1-x1 N (0≦x1<1). The first semiconductor layer 11 includes, for example, GaN. For example, the first semiconductor layer 11 is substantially parallel to the XY plane.

[0012] The first semiconductor layer 11 includes a first partial region 11a, a second partial region 11b, a third partial region 11c, a fourth partial region 11d, and a fifth partial region 11e.

[0013] A second direction from the first partial region 11a to the first electrode 51 intersects with the first direction (the X-axis direction). The second direction is, for example, the Z-axis direction.

[0014] The direction from the second partial region 11b to the second electrode 52 is along the second direction (e.g., the Z-axis direction). The direction from the third partial region 11c to the third electrode 53 is along the second direction (e.g., the Z-axis direction). The fourth partial region 11d is between the third partial region 11c and the first partial region 11a in the first direction (the X-axis direction). The fifth partial region 11e is between the second partial region 11b and the third partial region 11c in the first direction (the X-axis direction).

[0015] The first partial region 11a is a portion below the first electrode 51. The second partial region 11b is a portion below the second electrode 52. The third partial region 11c is a portion below the third electrode 53.

[0016] The second semiconductor layer 12 is Al x2 Ga 1-x2It includes N(0 < x2 < 1, x1 < x2). The second semiconductor layer 12 includes, for example, AlGaN. The second semiconductor layer 12 includes, for example, Al 0.3 Ga 0.7 N and the like.

[0017] The second semiconductor layer 12 includes a first semiconductor region 12a, a second semiconductor region 12b, and a third semiconductor region 12c. The direction from the fourth partial region 11d to the first semiconductor region 12a is along the second direction (for example, the Z-axis direction). The direction from the fifth partial region 11e to the second semiconductor region 12b is along the second direction (for example, the Z-axis direction). The third semiconductor region 12c is located between the first partial region 11a and the first electrode 51 in the second direction (for example, the Z-axis direction). The third semiconductor region 12c is the part under the first electrode 51.

[0018] In this example, the second semiconductor layer 12 further includes a fourth semiconductor region 12d. The fourth semiconductor region 12d is located between the second partial region 11b and the second electrode 52 in the second direction (for example, the Z-axis direction). The fourth semiconductor region 12d is the part under the second electrode 52.

[0019] The first compound member 31 includes Al y1 Ga 1-y1 N(0 < y1 ≤ 1, x2 < y1). The first compound member 31 includes, for example, AlN.

[0020] The first compound member 31 includes a plurality of first compound parts 31p. The plurality of first compound parts 31p are located between the third semiconductor region 12c and the first electrode 51. A part of the first electrode 51 is located between one of the plurality of first compound parts 31p and another one of the plurality of first compound parts 31p.

[0021] In this example, a substrate 15, a first intermediate layer 13, and a second intermediate layer 14 are provided. The first intermediate layer 13 is between the substrate 15 and the second semiconductor layer 12. The second intermediate layer 14 is between the first intermediate layer 13 and the second semiconductor layer 12. The first semiconductor layer 11 is between the second intermediate layer 14 and the second semiconductor layer 12. The substrate 15 is, for example, a silicon substrate. The first intermediate layer 13 is, for example, a buffer layer. The first intermediate layer 13 includes, for example, a plurality of stacked nitride semiconductor films. The second intermediate layer 14 includes, for example, p-type GaN.

[0022] The first electrode 51 is electrically connected to the third semiconductor region 12c. The second electrode 52 is electrically connected to the fourth semiconductor region 12d.

[0023] The distance between the first electrode 51 and the third electrode 53 is longer than the distance between the second electrode 52 and the third electrode 53 .

[0024] A carrier region 10E is formed in a region of the first semiconductor layer 11 facing the second semiconductor layer 12. The carrier region 10E is, for example, a two-dimensional electron gas.

[0025] A current flowing between the first electrode 51 and the second electrode 52 can be controlled by a voltage applied to the third electrode 53. The first electrode 51 functions as, for example, a drain electrode. The second electrode 52 functions as, for example, a source electrode. The third electrode 53 functions as, for example, a gate electrode. The semiconductor device 110 functions as, for example, a HEMT (High Electron Mobility Transistor).

[0026] In this example, a first insulating layer 41 is provided. A portion 41p of the first insulating layer 41 is located between the third partial region 11c and the third electrode 53 in the second direction (Z-axis direction). The portion 41p of the first insulating layer 41 functions as a gate insulating film.

[0027] As described above, in the semiconductor device 110, a plurality of first compound portions 31p are provided between the third semiconductor region 12c and the first electrode 51, and a part of the first electrode 51 is between the plurality of first compound portions 31p. The first semiconductor layer 11 and the second semiconductor layer 12 include a "region below" the plurality of first compound portions 31p. Due to the plurality of first compound portions 31p such as AlN, the carrier concentration in the "region below" becomes higher than the carrier concentration in the region between the third electrode 53 and the first electrode 51. In the "region below" of the plurality of first compound portions 31p, the carrier concentration can be locally increased. The first electrode 51 is electrically connected to the second semiconductor layer 12 in the region between the plurality of first compound portions 31p. As a result, a low resistance is obtained in the electrical connection between the first electrode 51 and the second semiconductor layer 12. As a result, a low on-resistance is obtained. It is possible to provide a semiconductor device capable of improving characteristics.

[0028] AlN has high electrical resistance. AlN is substantially insulating. Therefore, generally, when insulating AlN is provided between a semiconductor layer and an electrode, the contact area becomes small and the resistance becomes high. In the embodiment, a plurality of first compound portions 31p such as AlN are provided on the stack of the first semiconductor layer 11 and the second semiconductor layer 12. The plurality of first compound portions 31p can locally increase the carrier density under the plurality of first compound portions 31p. An electrical connection is obtained under the region between the plurality of first compound portions 31p. This allows low resistance to be obtained in the electrical connection.

[0029] As shown in FIG. 1, for example, a part of the first electrode 51 (a part between the multiple first compound portions 31p) is in contact with the third semiconductor region 12c.

[0030] For example, the above-mentioned one of the multiple first compound portions 31p and the above-mentioned another one of the multiple first compound portions 31p are in contact with the third semiconductor region 12c.

[0031] As shown in FIG. 1, the semiconductor device 110 may further include a second compound member 32. The second compound member 32 is Aly2 Ga 1-y2 It includes N(0 < y2 ≤ 1, x2 < y2). The second compound member 32 includes, for example, AlN. The fourth semiconductor region 12d is located between the second partial region 11b and the second electrode 52 in the second direction (Z-axis direction).

[0032] The second compound member 32 includes a plurality of second compound portions 32p. The plurality of second compound portions 32p are located between the fourth semiconductor region 12d and the second electrode 52. A part of the second electrode 52 is located between one of the plurality of second compound portions 32p and another one of the plurality of second compound portions 32p. Thereby, for example, in the "lower region" of the plurality of second compound portions 32p, the carrier concentration can be locally increased. The second electrode 52 is electrically connected to the second semiconductor layer 12 in the region between the plurality of second compound portions 32p. Thereby, a low resistance is obtained in the electrical connection between the second electrode 52 and the second semiconductor layer 12. Thereby, a low on-resistance is obtained. A semiconductor device capable of improving characteristics can be provided.

[0033] As shown in FIG. 1, for example, a part of the second electrode 52 (the part between the plurality of second compound portions 32p) is in contact with the fourth semiconductor region 12d.

[0034] For example, one of the above-mentioned plurality of second compound portions 32p and another one of the above-mentioned plurality of second compound portions 32p are in contact with the fourth semiconductor region 12d.

[0035] In the semiconductor device 110, at least a part of the third electrode 53 is located between the first semiconductor region 12a and the second semiconductor region 12b in the first direction (X-axis direction). It becomes easier to obtain a normally-off operation.

[0036] In the embodiment, the distance between one of the plurality of first compound portions 31p and another one of the plurality of first compound portions 31p adjacent thereto is, for example, 100 nm or more and 2000 nm or less. When this distance is 350 nm or more, for example, it is easy to improve the adhesion of the first electrode 51. When this distance is 700 nm or less, for example, it is possible to further increase the carrier concentration.

[0037] The width of one of the first compound portions 31p along the direction from one of the first compound portions 31p to another adjacent one of the first compound portions 31p is, for example, 100 nm or more and 2000 nm or less. When this width is 350 nm or more, for example, a stable interface is easily obtained between the first compound portions 31p and the second semiconductor layer 12. When this width is 700 nm or less, for example, the path of the electrical connection can be shortened.

[0038] Hereinafter, examples of the patterns of the first compound member 31 and the second compound member 32 will be described.

[0039] 2(a) to 2(c) are schematic plan views illustrating the semiconductor device according to the first embodiment. Figures 2(a) to 2(c) are plan views seen from the arrow AA in Figure 1. The cross section taken along the line A1-A2 in Figure 2(a) corresponds to Figure 1. The semiconductor devices 110a and 110b illustrated in Figures 2(b) and 2(c) have the same configuration as the semiconductor device 110, except for the pattern of the plurality of first compound portions 31p and the pattern of the plurality of second compound portions 32p.

[0040] 2(a) (semiconductor device 110), the direction from one of the first compound portions 31p to another of the first compound portions 31p has a component in the first direction (X-axis direction). The first compound portions 31p are, for example, striped and extending along the Y-axis direction.

[0041] 2(a) (the semiconductor device 110), the direction from one of the second compound portions 32p to another of the second compound portions 32p has a component in the first direction (X-axis direction). The second compound portions 32p are, for example, striped and extending along the Y-axis direction.

[0042] In the example (semiconductor device 110b) shown in FIG. 2(c), the direction from one of the multiple first compound portions 31p to another of the multiple first compound portions 31p has a component of a third direction intersecting a plane (XZ plane) including the first direction and the second direction. The third direction is, for example, the Y-axis direction. The multiple first compound portions 31p are, for example, striped and extending along the X-axis direction.

[0043] 2(c) (semiconductor device 110b), the direction from one of the second compound portions 32p to another of the second compound portions 32p has a component in a third direction (e.g., the Y-axis direction). The second compound portions 32p are, for example, striped and extending along the X-axis direction.

[0044] In the example (semiconductor device 110a) shown in Fig. 2(b), the island-shaped first compound portions 31p are aligned along the X-axis direction and the Y-axis direction. In the example (semiconductor device 110a) shown in Fig. 2(b), the island-shaped second compound portions 32p are aligned along the X-axis direction and the Y-axis direction.

[0045] In the embodiment, the pattern of the first compound portions 31p and the pattern of the second compound portions 32p can be modified in various ways. For example, the pattern of the first compound portions 31p illustrated in FIG. 2(a) and the pattern of the second compound portions 32p illustrated in FIG. 2(c) may be combined.

[0046] Two of the plurality of first compound portions 31p may be consecutive to each other. For example, the ends of two of the plurality of first compound portions 31p illustrated in FIG. 2(a) may be connected. Two of the plurality of second compound portions 32p may be consecutive to each other. For example, the ends of two of the plurality of second compound portions 32p illustrated in FIG. 2(a) may be connected.

[0047] (Second Embodiment) FIG. 3 is a schematic cross-sectional view illustrating a semiconductor device according to the second embodiment. As shown in FIG. 3, the semiconductor device 120 according to the embodiment includes a first electrode 51, a second electrode 52, a third electrode 53, a first semiconductor layer 11, a second semiconductor layer 12, and a first compound member 31. The semiconductor device 120 further includes a third compound member 33. The first insulating layer 41 includes a first insulating region 41a. The other configurations in the semiconductor device 120 are the same as those of the semiconductor device 110. Hereinafter, examples of the third compound member 33 and the first insulating region 41a will be described.

[0048] The third compound member 33 contains Al y3 Ga 1-y3 N (0 < y3 ≦ 1, x2 < y3). The third compound member 33 includes, for example, AlN. The third compound member 33 may have, for example, the same configuration and material as the first compound member 31. The third compound member 33 may have, for example, the same configuration and material as the second compound member 32.

[0049] The first semiconductor layer 11 further includes a sixth partial region 11f. The sixth partial region 11f is between the third partial region 11c and the fourth partial region 11d in the first direction (X-axis direction). The second semiconductor layer 12 further includes a fifth semiconductor region 12e. The direction from the sixth partial region 11f to the fifth semiconductor region 12e is along the second direction (for example, the Z-axis direction).

[0050] The first semiconductor region 12a is located between the fourth partial region 11d and the third compound member 33 in the second direction (Z-axis direction). The first insulating region 41a of the first insulating layer 41 is located between at least a part of the third electrode 53 and the third compound member 33 in the first direction (X-axis direction).

[0051] The carrier concentration is locally high in the portion located under the third compound member 33. This makes it possible to alleviate the concentration of the electric field between the third electrode 53 and the first electrode 51. This makes it possible to improve, for example, the breakdown voltage. According to the second embodiment, it is possible to provide a semiconductor device capable of improving characteristics.

[0052] For example, the third compound member 33 is in contact with the first semiconductor region 12a. For example, the first insulating region 41a is in contact with the fifth semiconductor region 12e.

[0053] The third compound member 33 may be continuous with one of the plurality of first compound portions 31p.

[0054] 3, the third electrode 53 includes an end 53e. The end 53e is an end on the side of the first electrode 51. The direction from another end 53f of the third electrode 53 to the end 53e is along the X-axis direction. In the example shown in FIG. 3, the position of the third compound member 33 in the X-axis direction is between the position of the end 53e in the X-axis direction and the position of the first electrode 51 in the X-axis direction.

[0055] FIG. 4 is a schematic cross-sectional view illustrating the semiconductor device according to the second embodiment. 4, the semiconductor device 121 according to the embodiment further includes a fourth compound member 34. The first insulating layer 41 includes a second insulating region 41b. Other configurations of the semiconductor device 121 are similar to those of the semiconductor device 120. Examples of the fourth compound member 34 and the second insulating region 41b will be described below.

[0056] The fourth compound member 34 is Al y4 Ga 1-y4It includes N(0 < y4 ≤ 1, x2 < y4). The fourth compound member 34 includes, for example, AlN. The fourth compound member 34 may have, for example, the same configuration and material as the first compound member 31. The fourth compound member 34 may have, for example, the same configuration and material as the second compound member 32.

[0057] The first semiconductor layer 11 further includes a seventh partial region 11g. The seventh partial region 11g is located between the fifth partial region 11e and the third partial region 11c in the first direction (X-axis direction). The second semiconductor layer 12 further includes a sixth semiconductor region 12f. The direction from the seventh partial region 11g to the sixth semiconductor region 12f is along the second direction (Z-axis direction).

[0058] The second semiconductor region 12b is located between the fifth partial region 11e and the fourth compound member 34 in the second direction (Z-axis direction). The second insulating region 41b of the first insulating layer 41 is located between the fourth compound member 34 and at least a part of the third electrode 53 in the first direction (X-axis direction).

[0059] The third compound member 33 may be continuous with the first compound member 31. The third compound member 33 may be continuous with at least one of a plurality of first compound parts 31p.

[0060] In the portion located under the fourth compound member 34, the carrier concentration becomes locally high. Thereby, the concentration of the electric field between the second electrode 52 and the third electrode 53 can be alleviated. Thereby, for example, the breakdown voltage can be improved. According to the second embodiment, a semiconductor device capable of improving characteristics can be provided.

[0061] For example, the fourth compound member 34 is in contact with the second semiconductor region 12b. For example, the second insulating region 41b is in contact with the sixth semiconductor region 12f.

[0062] As shown in FIGS. 3 and 4, the semiconductor devices 120 and 121 further include a fifth compound member 35. The fifth compound member 35 is Al y5 Ga 1-y5It includes N(0 < y5 ≤ 1, x2 < y5). The fifth compound member 35 includes, for example, AlN. The fifth compound member 35 may have, for example, the same configuration and material as the first compound member 31. The fifth compound member 35 may have, for example, the same configuration and material as the second compound member 32.

[0063] For example, between at least a part of the fifth compound member 35 and the first semiconductor layer 11, there is a part of the second semiconductor layer 12. Between at least a part of the fifth compound member 35 and the third compound member 33, there is a first insulating region 41a of the first insulating layer 41.

[0064] Another part of the fifth compound member 35 is between the third electrode 53 and the first semiconductor layer 11. Another part of the fifth compound member 35 is between the third electrode 53 and a part 41p of the first insulating layer 41.

[0065] The fifth compound member 35 includes an end portion 35e. The end portion 35e is the end portion on the side of the first electrode 51. The direction from another end portion 35f of the fifth compound member 35 to the end portion 35e is along the X-axis direction. In the example shown in FIGS. 3 and 4, between the position of the end portion 53e in the X-axis direction and the position of the third compound member 33 in the X-axis direction, there is the position of the end portion 35e in the X-axis direction.

[0066] FIG. 5 is a schematic cross-sectional view illustrating a semiconductor device according to the second embodiment. As shown in FIG. 5, in the semiconductor device 122 according to the embodiment, the third compound member 33 includes a plurality of third compound portions 33p. Other configurations in the semiconductor device 122 are the same as those of the semiconductor device 120. Hereinafter, examples of the plurality of third compound portions 33p will be described.

[0067] Between one of the plurality of third compound portions 33p and another one of the plurality of third compound portions 33p, there is a part of the first insulating layer 41. By the plurality of third compound portions 33p, for example, the profile of the electric field can be controlled. More effectively, the concentration of the electric field can be alleviated.

[0068] Two of the plurality of third compound portions 33p may be continuous with each other. For example, two of the plurality of third compound portions 33p may be connected to each other at their respective ends.

[0069] The fourth compound member 34 may include a plurality of fourth compound portions. A part of the first insulating layer 41 may be present between one of the plurality of fourth compound portions and another of the plurality of fourth compound portions.

[0070] Third embodiment FIG. 6 is a schematic cross-sectional view illustrating the semiconductor device according to the third embodiment. As shown in FIG. 6, the semiconductor device 130 according to the embodiment includes a first electrode 51, a second electrode 52, a third electrode 53, a first semiconductor layer 11, a second semiconductor layer 12, a third compound member 33 (compound member), and a first insulating layer 41.

[0071] The position of the third electrode 53 in a first direction (e.g., the X-axis direction) from the second electrode 52 to the first electrode 51 is between the position of the second electrode 52 in the first direction and the position of the first electrode 51 in the first direction.

[0072] The first semiconductor layer 11 is Al x1 Ga 1-x1 N (0≦x1<1). The first semiconductor layer 11 includes first to sixth partial regions 11a to 11f. A second direction (e.g., the Z-axis direction) from the first partial region 11a to the first electrode 51 intersects with the first direction. A direction from the second partial region 11b to the second electrode 52 is aligned with the second direction. A direction from the third partial region 11c to the third electrode 53 is aligned with the second direction. The fourth partial region 11d is between the third partial region 11c and the first partial region 11a in the first direction. The fifth partial region 11e is between the second partial region 11b and the third partial region 11c in the first direction. The sixth partial region 11f is between the third partial region 11c and the fourth partial region 11d in the first direction.

[0073] The second semiconductor layer 12 is Al x2 Ga 1-x2It includes N(0 < x2 < 1, x1 < x2). The second semiconductor layer 12 includes a first semiconductor region 12a and a second semiconductor region 12b. The direction from the fourth partial region 11d to the first semiconductor region 12a is along the second direction (for example, the Z-axis direction). The direction from the fifth partial region 11e to the second semiconductor region 12b is along the second direction.

[0074] The third compound member 33 (compound member) is Al y3 Ga 1-y3 It includes N(0 < y3 ≤ 1, x2 < y3). The direction from the fourth partial region 11d to the third compound member 33 is along the second direction (Z-axis direction).

[0075] The first insulating layer 41 includes a first insulating region 41a. A part of the first semiconductor region 12a is between the fourth partial region 11d and the third compound member 33 in the second direction (Z-axis direction). Another part of the first semiconductor region 12a is between the sixth partial region 11f and the first insulating region 41a in the second direction (Z-axis direction).

[0076] In the part located under the third compound member 33, the carrier concentration becomes locally high. Thereby, the concentration of the electric field between the third electrode 53 and the first electrode 51 can be alleviated. Thereby, for example, the breakdown voltage can be improved. According to the third embodiment, a semiconductor device capable of improving characteristics can be provided.

[0077] For example, the third compound member 33 is in contact with a part of the first semiconductor region 12a. For example, the first insulating region 41a is in contact with 1 another part of the semiconductor region 12a.

[0078] In the semiconductor device 130, a first doped region 12A may be provided between the first electrode 51 and the first partial region 11a. A second doped region 12B may be provided between the second electrode 52 and the second partial region 11b. The impurity concentration in these doped regions is higher than the impurity concentration in the first semiconductor layer 11. The impurity contains, for example, at least one selected from the group consisting of Si, Ge, C, and Ti. These doped regions provide a low resistance in the electrical connection between the semiconductor layer and the electrode. When these doped regions are provided, the first compound member 31 or the second compound member 32 may be omitted. These doped regions may be part of the second semiconductor layer 12. These doped regions substantially contain Al x2 Ga 1-x2 and may contain N (0 < x2 < 1, x1 < x2). At least a part of the doped region contains Al x2 Ga 1-x2 N (0 < x2 < 1, x1 < x2) and an impurity.

[0079] In the semiconductor devices 120, 121, 122, and 130, the position of the end portion 35e in the X-axis direction is between the position of the end portion 53e in the X-axis direction and the position of the third compound member 33 in the X-axis direction. Since the end portion 53e of the third electrode 53 is far from the first electrode 51, for example, short circuits and the like are suppressed, and a high breakdown voltage can be obtained.

[0080] FIGS. 7 to 10 are schematic cross-sectional views illustrating semiconductor devices according to the embodiment. As shown in FIGS. 7 to 10, in the semiconductor devices 120a, 121a, 122a, and 130a, the position of the end portion 53e in the X-axis direction is between the position of the end portion 35e in the X-axis direction and the position of the third compound member 33 in the X-axis direction. The configurations of the semiconductor devices 120a, 121a, 122a, and 130a other than this are the same as the configurations of the semiconductor devices 120, 121, 122, and 130.

[0081] In the semiconductor devices 120a, 121a, 122a, and 130a, the end 53e of the third electrode 53 may function as, for example, a field plate. This reduces the concentration of the electric field. For example, a high breakdown voltage can be obtained.

[0082] 11 to 14 are schematic cross-sectional views illustrating the semiconductor device according to the embodiment. 11 to 14, the semiconductor devices 120b, 121b, 122b, and 130b include a conductive member 54. Other configurations of the semiconductor devices 120b, 121b, 122b, and 130b are similar to those of the semiconductor devices 120, 121, 122, and 130.

[0083] The conductive member 54 is electrically connected to the third electrode 53. The conductive member 54 includes a first conductive portion 54A and a second conductive portion 54B. 3 The third electrode 53 is located between the partial region 11c and the first conductive portion 54A. The second conductive portion 54B is connected to the first conductive portion 54A. The direction from the first conductive portion 54A to the second conductive portion 54B is along the first direction (X-axis direction).

[0084] The conductive member 54 may function as a field plate. The conductive member 54 reduces the concentration of an electric field. For example, a high breakdown voltage can be obtained.

[0085] The conductive member 54 includes an end 54e. The end 54e is the end on the side of the first electrode 51. The direction from another end 54f of the conductive member 54 to the end 54e is along the X-axis direction.

[0086] The position of the end 54e in the X-axis direction is between the position of the third electrode 53 in the X-axis direction and the position of the first electrode 51 in the X-axis direction. The position of the end 54e in the X-axis direction is between the position of the end 53e in the X-axis direction and the position of the first electrode 51 in the X-axis direction.

[0087] In the semiconductor devices 120b, 121b, 122b, and 130b, the position of the third compound member 33 in the X-axis direction is between the position of the end 54e in the X-axis direction and the position of the first electrode 51 in the X-axis direction.

[0088] 15 to 18 are schematic cross-sectional views illustrating the semiconductor device according to the embodiment. 15 to 18, in the semiconductor devices 120c, 121c, 122c, and 130c, the position of the end 54e of the conductive member 54 is different from that in the semiconductor devices 120b, 121b, 122b, and 130b. Except for this, the configurations of the semiconductor devices 120c, 121c, 122c, and 130c are similar to the configurations of the semiconductor devices 120b, 121b, 122b, and 130b.

[0089] In the semiconductor devices 120c, 121c, 122c, and 130c, the end 54e overlaps with the third compound member 33 in the second direction (Z-axis direction). In the semiconductor devices 120c, 121c, 122c, and 130c, at least a portion of the third compound member 33 is between the second conductive portion 54B and the second semiconductor layer 12 in the second direction (Z-axis direction). For example, at least a portion of the third compound member 33 is covered by the second conductive portion 54B. For example, the on-resistance can be reduced.

[0090] 19 to 22 are schematic cross-sectional views illustrating the semiconductor device according to the embodiment. 19 to 22, in the semiconductor devices 120d, 121d, 122d, and 130d, the position of the end 53e in the X-axis direction is between the position of the end 35e in the X-axis direction and the position of the third compound member 33 in the X-axis direction. The remaining configurations of the semiconductor devices 120d, 121d, 122d, and 130d are similar to the configurations of the semiconductor devices 120b, 121b, 122b, and 130b. The positional relationship between the end 53e, the end 35e, and the third compound member 33 as described above can further improve reliability, for example.

[0091] 23 to 26 are schematic cross-sectional views illustrating the semiconductor device according to the embodiment. 23 to 26, the semiconductor devices 120e, 121e, 122e, and 130e include a second insulating layer 42. Except for this, the configurations of the semiconductor devices 120e, 121e, 122e, and 130e are similar to the configurations of the semiconductor devices 120d, 121d, 122d, and 130d.

[0092] The second insulating layer 42 includes, for example, a first insulating portion 42a and a second insulating portion 42b. The first insulating portion 42a is between a part of the second semiconductor layer 12 (for example, the fifth semiconductor region 12e) and a part of the fifth compound member 35 in the Z-axis direction. The first insulating portion 42a makes it difficult for the carrier region 10E to be formed below the first insulating portion 42a. For example, the concentration of the electric field can be further alleviated. For example, the threshold voltage can be appropriately increased. For example, normally-on operation can be easily obtained.

[0093] The second insulating portion 42b is located in the Z-axis direction between a part of the second semiconductor layer 12 (for example, the second semiconductor region 12b) and a part of the fifth compound member 35. The second insulating portion 42b makes it difficult for a carrier region 10E to be formed below the second insulating portion 42b. For example, the concentration of the electric field can be further alleviated. For example, the threshold voltage can be appropriately increased. For example, normally-on operation can be more easily obtained. 。

[0094] The second insulating layer 42 contains, for example, SiN. The nitrogen concentration in the second insulating layer 42 is higher than the nitrogen concentration in the first insulating layer 41. The oxygen concentration in the first insulating layer 41 is higher than the oxygen concentration in the second insulating layer 42.

[0095] 27 to 30 are schematic cross-sectional views illustrating the semiconductor device according to the embodiment. 27 to 30, the semiconductor devices 120f, 121f, 122f, and 130f include a conductive member 55. Except for this, the configurations of the semiconductor devices 120f, 121f, 122f, and 130f are similar to the configurations of the semiconductor devices 120a, 121a, 122a, and 130a.

[0096] The conductive member 55 is electrically connected to the second electrode 52. The conductive member 55 includes a third conductive portion 55A and a fourth conductive portion 55B. In the second direction (Z-axis direction), the second electrode 52 is between the second partial region 11b and the third conductive portion 55A. The fourth conductive portion 55B is connected to the third conductive portion 55A. The direction from the third conductive portion 55A to the fourth conductive portion 55B is along the first direction (X-axis direction).

[0097] The conductive member 55 may function as a field plate. The concentration of an electric field is alleviated by the conductive member 55. For example, a high breakdown voltage can be obtained.

[0098] The conductive member 55 includes an end 55e. The end 55e is an end on the side of the first electrode 51. The direction from another end 55f of the conductive member 55 to the end 55e is along the X-axis direction.

[0099] The position of end 55e in the X-axis direction is between the position of third electrode 53 in the X-axis direction and the position of first electrode 51 in the X-axis direction. The position of end 55e in the X-axis direction is between the position of end 53e in the X-axis direction and the position of first electrode 51 in the X-axis direction.

[0100] In the embodiment, the first to third electrodes 51 to 53 include, for example, Ti. The conductive members 54 and 55 include, for example, at least one selected from the group consisting of Ti and Al. The first insulating layer 41 includes, for example, at least one selected from the group consisting of silicon oxide, silicon nitride, silicon oxynitride, and aluminum oxide. The second insulating layer 42 includes, for example, at least one selected from the group consisting of silicon nitride and silicon oxynitride.

[0101] According to the embodiment, it is possible to provide a semiconductor device capable of improving characteristics.

[0102] In this specification, the term "nitride semiconductor" refers to B x In y Al z Ga 1-x-y-z It includes all semiconductors with compositions in which the composition ratios x, y, and z are changed within the respective ranges in the chemical formula N (0≦x≦1, 0≦y≦1, 0≦z≦1, x+y+z≦1). Furthermore, in the above chemical formula, those that further contain Group V elements other than N (nitrogen), those that further contain various elements added to control various physical properties such as the conductivity type, and those that further contain various elements that are unintentionally included are also included in the "nitride semiconductor".

[0103] In this specification, "vertical" and "parallel" do not only mean strictly vertical and strictly parallel, but also include, for example, variations in the manufacturing process, and may mean substantially vertical and substantially parallel.

[0104] The above describes the embodiments of the present invention with reference to specific examples. However, the present invention is not limited to these specific examples. For example, the specific configurations of each element, such as a semiconductor layer, an electrode, and an insulating layer, included in a semiconductor device are included in 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 from the known range.

[0105] Furthermore, any combination of two or more elements of each of the specific examples, 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.

[0106] In addition, all semiconductor devices that can be implemented by those skilled in the art by appropriately modifying the design based on the semiconductor device described above as an embodiment of the present invention also belong to the scope of the present invention as long as they include the gist of the present invention.

[0107] In addition, within the scope of the concept of the present invention, a person skilled in the art may conceive of various modifications and alterations, and it will be understood that these modifications and alterations also fall within the scope of the present invention.

[0108] Although some 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 implemented 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 in the scope and spirit of the invention, and are included in the scope of the invention and its equivalents described in the claims. [Explanation of symbols]

[0109] 10E carrier region, 11... first semiconductor layer, 11a to 11g... first to seventh partial regions, 12... second semiconductor layer, 12A, 12B... first and second doped regions, 12a to 12f... first to sixth semiconductor regions, 13... first intermediate layer, 14... second intermediate layer, 15... substrate, 31-35...first to fifth compound members, 31p-33p...first to third compound portions, 35e, 35f...end portions, 41...first insulating layer, 41a, 41b...first and second insulating regions, 41p...part, 42...second insulating layer, 42a, 42b...first and second insulating portions, 51-53...first to third electrodes, 53e, 53f...end portions, 54...conductive member, 54A, 54B...first and second conductive portions, 54e, 54f...end portions, 55...conductive member, 55A, 55B...third and fourth conductive portions, 55e, 55f...end portions, 110, 110a, 110b, 120, 120a to 120f, 121, 121a to 121f, 122, 122a to 122f, 130, 130a to 130f...semiconductor device, AA...arrow

Claims

1. A first electrode; A second electrode; a third electrode, the position of the third electrode in a first direction from the second electrode to the first electrode being between the position of the second electrode in the first direction and the position of the first electrode in the first direction; A ｘ１ G １－ｘ１ N (0≦x1<1), the first semiconductor layer including 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, a second direction from the first partial region to the first electrode intersects with the first direction, a direction from the second partial region to the second electrode is along the second direction, a direction from the third partial region to the third electrode is along the second direction, the fourth partial region is between the third partial region and the first partial region in the first direction, the fifth partial region is between the second partial region and the third partial region in the first direction, and the sixth partial region is between the third partial region and the fourth partial region in the first direction; A ｘ２ G １－ｘ２ N (0<x2<1, x1<x2), the second semiconductor layer including a first semiconductor region and a second semiconductor region, a direction from the fourth partial region to the first semiconductor region is along the second direction, a direction from the fifth partial region to the second semiconductor region is along the second direction, and at least a portion of the third electrode is between the first semiconductor region and the second semiconductor region in the first direction; A ｙ３ G １－ｙ３ N (0<y3≦1, x2<y3), and a direction from the fourth partial region to the compound member is along the second direction; a first insulating layer including a first insulating region; A ｙ５ G １－ｙ５ a fifth compound member including N (0<y5≦1, x2<y5); Equipped with a portion of the first semiconductor region is located between the fourth region and the compound member in the second direction; Another portion of the first semiconductor region is between the sixth portion region and the first insulating region in the second direction, the first insulating region is in contact with the other portion of the first semiconductor region; a portion of the second semiconductor layer is between at least a portion of the fifth compound member and the first semiconductor layer; A portion of the first insulating layer is Between the first semiconductor layer and the third electrode, Between the third partial region and the third electrode, Between the first semiconductor region and the third electrode, and provided between the second semiconductor region and the third electrode, A portion of the fifth compound member is Between the first semiconductor layer and the portion of the first insulating layer, Between the third region and the portion of the first insulating layer, between the first semiconductor region and the portion of the first insulating layer; and provided between the second semiconductor region and the portion of the first insulating layer; A semiconductor device, wherein the material of the compound member is the same as the material of the fifth compound member.

2. The semiconductor device according to claim 1 , wherein the compound member includes AlN.

3. The semiconductor device according to claim 2 , wherein the compound member is spaced apart from the first electrode.

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