Semiconductor device

Abstract

To provide a semiconductor device capable of improving characteristics.SOLUTION: According to an embodiment, a semiconductor device includes first to third electrodes, a semiconductor member, a first conductive member, first and second insulation members, and a first nitride member. The first nitride member includes a first nitride region. The first nitride region is located between a first insulation portion and a second insulation portion of the second insulation member in a first direction. The first nitride region is located between a third portion of a second conductor portion of a second semiconductor region and a second conductive region of the first conductive member in a second direction.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] Embodiments of the present invention relate to a semiconductor device.

Background Art

[0002] For example, there is a semiconductor device using a nitride semiconductor. In the semiconductor device, improvement in characteristics is 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 capable of improving 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, a semiconductor member, a first conductive member, a first insulating member, a second insulating member, and a first nitride member. A position of the third electrode in a first direction from the first electrode to the second electrode is between a position of the first electrode in the first direction and a position of the second electrode in the first direction. The semiconductor member includes a first semiconductor region and a second semiconductor region. The first semiconductor region contains Al x1 Ga 1-x1It includes N(0≦x1<1). The first semiconductor region 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 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 second semiconductor region contains Al x2 Ga 1-x2 It includes N(0<x2≦1, x1<x2). The second semiconductor region includes a first semiconductor part and a second 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 second semiconductor part includes a first part, a second part, and a third part between the first part and the second part. The position of the second part in the first direction is between the position of the first part in the first direction and the position of the second electrode in the first direction. The first conductive member includes a first conductive region and a second conductive region. The first conductive region overlaps the third electrode in the second direction. The first part is between the fifth partial region and a part of the first conductive region. The first conductive member is electrically connected to one of the first electrode and the third electrode. Or, the first conductive member can be electrically connected to the one. The first insulating member includes a first insulating region. The first insulating region is between the third partial region and the third electrode in the second direction. The second insulating member includes a first insulating part and a second insulating part. The first insulating part is between the first part and the first conductive region in the second direction. The second part is between the fifth partial region and the second insulating part. The first nitride member is Al x3 Ga 1-x3 N(0≦x3<1) or In y1 Aly2 Ga 1-y1-y2 It contains N(0 < y1 ≦ 1, 0 ≦ y2 ≦ 1, y1 + y2 ≦ 1). The first nitride member includes a first nitride region. The first nitride region is between the first insulating portion and the second insulating portion in the first direction. The first nitride region is between the third portion and the second conductive region in the second direction.

Brief Description of the Drawings

[0006]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Modes for Carrying Out the Invention

[0007] Hereinafter, each embodiment 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 compound portion, the ratio of the sizes between compound portions, etc. are not necessarily the same as the actual ones. Even when representing the same compound portion, the dimensions and ratios may be represented differently in the drawings. In the present specification and each figure, the same reference numerals are given to the same elements as those described above with respect to the previously shown figures, and the detailed description will be omitted as appropriate.

[0008] (First Embodiment) FIG. 1 is a schematic cross-sectional view illustrating a semiconductor device according to the first embodiment. As shown in FIG. 1, the semiconductor device 110 according to the embodiment includes a first electrode 51, a second electrode 52, a third electrode 53, a semiconductor member 10M, a first conductive member 61, a first insulating member 41, a second insulating member 42, and a first nitride member 31.

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

[0010] 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. For example, at least a part of the third electrode 53 is between the first electrode 51 and the second electrode 52 in the first direction D1.

[0011] The semiconductor member 10M includes a first semiconductor region 10 and a second semiconductor region 20. In this example, the semiconductor device 110 includes a substrate 10s and a nitride semiconductor layer 10B. The nitride semiconductor layer 10B is provided between the substrate 10s and the semiconductor member 10M. For example, the nitride semiconductor layer 10B is provided on the substrate 10s. The semiconductor member 10M is provided on the nitride semiconductor layer 10B. For example, the first semiconductor region 10 is provided on the nitride semiconductor layer 10B. The second semiconductor region 20 is provided on the first semiconductor region 10. The first to third electrodes 51 to 53 are provided on the semiconductor member 10M. The substrate 10s may be, for example, a silicon substrate or a SiC substrate. The nitride semiconductor layer 10B includes, for example, AlGaN.

[0012] The first semiconductor region 10 contains Al x1 Ga 1-x1 N (0 ≦ x1 < 1). The first semiconductor region 10 is, for example, a GaN layer. The composition ratio x1 of Al in the first semiconductor region 10 may be, for example, 0 or more and 0.1 or less.

[0013] For example, the first semiconductor region 10 contains GaN. The first semiconductor region 10 includes a first partial region 11, a second partial region 12, a third partial region 13, a fourth partial region 14, and a fifth partial region 15. The second direction D2 from the first partial region 11 to the first electrode 51 intersects the first direction D1. The second direction D2 may be, for example, the Z-axis direction.

[0014] The direction from the second partial region 12 to the second electrode 52 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.

[0015] The portion of the first semiconductor region 10 that overlaps with the first electrode 51 in the second direction D2 corresponds to the first partial region 11. The portion of the first semiconductor region 10 that overlaps with the second electrode 52 in the second direction D2 corresponds to the second partial region 12. The portion of the first semiconductor region 10 that overlaps with the third electrode 53 in the second direction D2 corresponds to the third partial region 13.

[0016] 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 first to fifth partial regions 11 to 15 may be continuous with each other. The boundaries between the first to fifth partial regions 11 to 15 may be clear or unclear.

[0017] The second semiconductor region 20 contains Al x2 Ga 1-x2 N (0 < x2 ≤ 1, x1 < x2). The second semiconductor region 20 is, for example, an AlGaN layer. The composition ratio x2 of Al in the second semiconductor region 20 may be, for example, 0.25 or more and 0.4 or less.

[0018] The second semiconductor region 20 includes a first semiconductor portion 21 and a second semiconductor portion 22. 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 second semiconductor portion 22 includes a first portion 22a, a second portion 22b, and a third portion 22c. The third portion 22c is between the first portion 22a and the second portion 22b. The position of the second portion 22b in the first direction D1 is between the position of the first portion 22a in the first direction D1 and the position of the second electrode 52 in the first direction D1. The first to third portions 22a to 22c may be continuous with each other. The boundaries between the first to third portions 22a to 22c may be clear or unclear.

[0019] For example, the first electrode 51 is electrically connected to the first semiconductor portion 21. For example, the second electrode 52 is electrically connected to the second semiconductor portion 22.

[0020] The first conductive member 61 includes a first conductive region 61a and a second conductive region 61b. The first conductive region 61a overlaps the third electrode 53 in the second direction D2. The second conductive region 61b does not overlap the third electrode 53 in the second direction D2. The position of the second conductive region 61b 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. The second conductive region 61b corresponds to a protruding portion that protrudes toward the side of the second electrode 52 with respect to the third electrode 53. The second conductive region 61b corresponds to, for example, an eaves portion.

[0021] The first portion 22a is between the fifth partial region 15 and a part of the first conductive region 61a in the second direction D2. In this example, the third electrode 53 is between the fifth partial region 15 and the first conductive region 61a in the second direction D2. At least a part of the second portion 22b does not overlap the first conductive member 61 in the second direction D2.

[0022] In an embodiment, the first conductive member 61 is electrically connected to one of the first electrode 51 and the third electrode 53. Alternatively, it may be electrically connected to one of the first electrode 51 and the third electrode 53. In the first embodiment, the first conductive member 61 is electrically connected to the first electrode 51. Terminals electrically connected to the first conductive member 61 and terminals electrically connected to the first electrode 51 are provided, and these terminals may be electrically connected during use of the semiconductor device.

[0023] For example, the first conductive member 61 includes a first conductive end portion 61e. The first conductive end portion 61e is the end on the side of the second electrode 52 in the first direction D1. The position of the first conductive end portion 61e 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.

[0024] The first insulating member 41 includes a first insulating region 41a. The first insulating region 41a is between the third partial region 13 and the third electrode 53 in the second direction D2.

[0025] The second insulating member 42 includes a first insulating portion 42a and a second insulating portion 42b. The first insulating portion 42a is between the first partial region 22a and the first conductive region 61a in the second direction D2. The second partial region 22b is between the fifth partial region 15 and the second insulating portion 42b.

[0026] The first nitride member 31 contains Al x3 Ga 1-x3 N (0 ≤ x3 < 1). The first nitride member 31 is, for example, a GaN layer or an AlGaN layer. The composition ratio x3 of Al in the first nitride member 31 may be, for example, 0 or more and 0.5 or less. For example, the composition ratio x3 of Al in the first nitride member 31 is lower than the composition ratio x2 of Al in the second semiconductor region 20 (for example, the second semiconductor portion 22).

[0027] The first nitride member 31 includes a first nitride region 31a. The first nitride region 31a is located between the first insulating portion 42a and the second insulating portion 42b in the first direction D1. The first nitride region 31a is located between the third portion 22c and the second conductive region 61b in the second direction D2. The first nitride region 31a overlaps with the second conductive region 61b in the second direction D2.

[0028] 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. For example, the first electrode 51 functions as a source electrode. The second electrode 52 functions as a drain electrode. The third electrode 53 functions as a gate electrode. The first insulating region 41a functions as a gate insulating film. The semiconductor device 110 is, for example, a transistor. For example, the distance between the first electrode 51 and the third electrode 53 is shorter than the distance between the third electrode 53 and the second electrode 52.

[0029] A carrier region 10C is formed in a portion of the first semiconductor region 10 facing the second semiconductor region 20. 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).

[0030] The first conductive member 61 functions as, for example, a field plate. As described above, in the embodiment, the second conductive region 61b (protrusion or eaves portion) is provided on the first conductive member 61. The first nitride region 31a (GaN or AlGaN) is provided in a portion overlapping with the second conductive region 61b. Thereby, in the region overlapping with the second conductive region 61b, the carrier concentration of the carrier region 10C locally decreases.

[0031] Generally, at the end of the second conductive region 61b (protrusion or overhang portion) (the first conductive end 61e), the electric field concentrates. Due to the concentration of the electric field, the breakdown voltage is likely to decrease. In the embodiment, in the region overlapping the second conductive region 61b, the carrier concentration can be locally lowered. Thereby, a high breakdown voltage can be easily obtained. According to the embodiment, a semiconductor device capable of improving characteristics can be provided.

[0032] In this example, the first nitride member 31 includes a second nitride region 31b and a third nitride region 31c. The first insulating portion 42a is between the first portion 22a and the second nitride region 31b. The second insulating portion 42b is between the second portion 22b and the third nitride region 31c. The first nitride region 31a, the second nitride region 31b, and the third nitride region 31c may be continuous with each other. The boundaries between the first nitride region 31a, the second nitride region 31b, and the third nitride region 31c may be clear or unclear. By providing the first nitride region 31a, the second nitride region 31b, and the third nitride region 31c continuously, the formation of the first nitride member 31 is easy.

[0033] In the first nitride member 31, the portion overlapping the second conductive region 61b in the second direction D2 corresponds to the first nitride region 31a. In the first nitride member 31, the portion between the first insulating portion 42a and the second insulating portion 42b in the first direction D1 corresponds to the first nitride region 31a. In this example, the first nitride region 31a is in contact with the third portion 22c. As will be described later, another layer (for example, an AlN layer) may be provided between the first nitride region 31a and the third portion 22c.

[0034] For example, the crystallinity of the first nitride region 31a may be higher than that of the second nitride region 31b and higher than that of the third nitride region 31c. At least a part of the first nitride region 31a may contain crystals. At least a part of the second nitride region 31b may be amorphous. At least a part of the third nitride region 31c may be amorphous.

[0035] The thickness t1 along the second direction D2 of the first nitride region 31a is, for example, 1 nm or more and 10 nm or less. When the thickness t1 is 1 nm or more, for example, a homogeneous first nitride region 31a can be easily obtained. When the thickness t1 is 10 nm or less, for example, crystal defects such as misfit Dislocation due to film stress are easily suppressed. The thickness t1 may be 3 nm or more and 5 nm or less. When the thickness t1 is 3 nm or more, for example, a homogeneous first nitride region 31a can be more easily obtained. When the thickness t1 is 3 nm or more, for example, the carrier concentration can be easily and stably controlled. When the thickness t1 is 5 nm or less, for example, crystal defects such as misfit Dislocation due to film stress are more easily suppressed.

[0036] In an embodiment, the second insulating member 42 contains silicon and nitrogen. The second insulating member 42 contains, for example, SiN. Such a second insulating member 42 makes it easy to obtain high quality in the semiconductor member 10M under the second insulating member 42.

[0037] For example, the first insulating member 41 contains silicon and oxygen. The first insulating member 41 contains, for example, silicon oxide (SiO2). For example, the first insulating member 41 substantially does not contain nitrogen. Or, the concentration of nitrogen in the first insulating member 41 is lower than the concentration of nitrogen in the second insulating member 42. Such a first insulating member 41 makes it easy to obtain, for example, a stable threshold voltage.

[0038] As shown in FIG. 1, the first insulating member 41 may further include a second insulating region 41b and a third insulating region 41c. The second insulating region 41b is between the first semiconductor portion 21 and the third electrode 53 in the first direction D1. The third insulating region 41c is between the third electrode 53 and the second semiconductor portion 22 in the first direction D1. At least a part of the third electrode 53 is between the first semiconductor portion 21 and the second semiconductor portion 22 in the first direction D1.

[0039] At least a part of the first insulating region 41a is located between the fourth partial region 14 and the fifth partial region 15 in the first direction D1. For example, a recess is provided in the semiconductor member 10M, and at least a part of the third electrode 53 is embedded in the recess. The semiconductor device 110 is a gate recess type transistor.

[0040] As shown in FIG. 1, the second insulating member 42 may include a third insulating portion 42c. The first semiconductor portion 21 is located between the fourth partial region 14 and the third insulating portion 42c.

[0041] As shown in FIG. 1, the first insulating member 41 further includes a fourth insulating region 41d. At least a part of the fourth insulating region 41d is located between the third electrode 53 and the first conductive member 61.

[0042] The first insulating member 41 may include a fifth insulating region 41e and a sixth insulating region 41f. The first semiconductor portion 21 is located between the fourth partial region 14 and the fifth insulating region 41e. The second semiconductor portion 22 is located between the fifth partial region 15 and the sixth insulating region 41f.

[0043] As shown in FIG. 1, let the length of the first nitride region 31a along the first direction D1 be the first length w1. The second semiconductor portion 22 includes an end 22p on the side of the third electrode 53. The second semiconductor portion 22 includes a portion 22q that overlaps with the second electrode 52 in the second direction D2. Let the distance in the first direction D1 between the end 22p on the side of the third electrode 53 of the second semiconductor portion 22 and the position of the portion 22q that overlaps with the second electrode 52 of the second semiconductor portion 22 in the second direction D2 be the second length w2. The first length w1 is, for example, 0.035 times or more and 0.5 times or less of the second length. With such a first length w1, for example, a region with a controlled carrier concentration is appropriately formed, and it is easy to effectively obtain a high breakdown voltage.

[0044] FIG. 2 is a schematic cross-sectional view illustrating a semiconductor device according to the first embodiment. As shown in FIG. 2, the semiconductor device 111 according to the embodiment includes a second nitride member 32. The configuration of the semiconductor device 111 other than this is the same as the configuration of the semiconductor device 110. For example, in the semiconductor device 111, the configurations of the first electrode 51, the second electrode 52, the third electrode 53, the semiconductor member 10M, the first conductive member 61, the first insulating member 41, the second insulating member 42, and the first nitride member 31 may be the same as those in the semiconductor device 110.

[0045] The second nitride member 32 contains Al x4 Ga 1-x4 N (0 <x4 ≦ 1, x3 <x4). The second nitride member 32 may be, for example, an AlN layer. The composition ratio x4 of Al in the second nitride member 32 may be, for example, 0.5 or more and 1.0 or less.

[0046] At least a part of the second nitride member 32 is between the first part 22a and the first insulating part 42a, and between the second part 22b and the second insulating part 42b. A part of the second nitride member 32 may be provided between the third part 22c and the first nitride region 31a.

[0047] By providing the second nitride member 32 as described above, high quality can be obtained in the second semiconductor portion 22. For example, damage to the second semiconductor portion 22 by the second insulating member 42 can be suppressed.

[0048] Also in the semiconductor device 111, in a region overlapping the second conductive region 61b, the carrier concentration can be locally lowered. A high breakdown voltage is easily obtained. A semiconductor device with improved characteristics can be provided.

[0049] For example, the second nitride member 32 may be in contact with the third part 22c and the first nitride region 31a.

[0050] As shown in FIG. 2, a part of the second nitride member 32 may be provided between the first semiconductor part 21 and the third insulating part 42c. For example, damage to the second semiconductor portion 22 by the second insulating member 42 can be suppressed.

[0051] The thickness t2 of the second nitride member 32 along the second direction D2 is, for example, 1 nm or more and 10 nm or less. When the thickness t2 is 1 nm or more, damage to the second semiconductor region 20 can be effectively suppressed, for example. When the thickness t2 is 10 nm or less, in the second nitride member 32, it is easy to suppress crystal defects such as Dislocation misfits due to film stress. The thickness t2 may be, for example, 3 nm or more and 5 nm or less. When the thickness t2 is 3 nm or more, damage to the second semiconductor region 20 can be more effectively suppressed. When the thickness t2 is 5 nm or less, it is easier to suppress crystal defects such as Dislocation misfits due to film stress.

[0052] (Second Embodiment) FIG. 3 is a schematic cross-sectional view illustrating a semiconductor device according to the second embodiment. As shown in FIG. 3, in the semiconductor device 112 according to the embodiment, the first conductive member 61 is electrically connected to the third electrode 53. The configuration of the semiconductor device 112 except for this is the same as the configuration of the semiconductor device 110. For example, in the semiconductor device 112, the configurations of the first electrode 51, the second electrode 52, the third electrode 53, the semiconductor member 10M, the first insulating member 41, the second insulating member 42, and the first nitride member 31 may be the same as those in the semiconductor device 110.

[0053] In the semiconductor device 112, a terminal electrically connected to the first conductive member 61 and a terminal electrically connected to the third electrode 53 are provided, and these terminals may be electrically connected during use of the semiconductor device.

[0054] Also in the semiconductor device 112, the first nitride region 31a is provided. The first nitride region 31a is between the first insulating portion 42a and the second insulating portion 42b in the first direction D1. The first nitride region 31a is between the third portion 22c and the second conductive region 61b in the second direction D2. The first nitride region 31a overlaps the second conductive region 61b in the second direction D2.

[0055] As a result, in the region overlapping with the second conductive region 61b, the carrier concentration in the carrier region 10C locally decreases. Thereby, a high breakdown voltage can be easily obtained. According to the embodiment, a semiconductor device with improved characteristics can be provided.

[0056] FIG. 4 is a schematic cross-sectional view illustrating a semiconductor device according to the second embodiment. As shown in FIG. 4, the semiconductor device 113 according to the embodiment includes a second nitride member 32. The configuration of the semiconductor device 113 excluding this is the same as the configuration of the semiconductor device 112. For example, in the semiconductor device 113, the configurations of the first electrode 51, the second electrode 52, the third electrode 53, the semiconductor member 10M, the first conductive member 61, the first insulating member 41, the second insulating member 42, and the first nitride member 31 may be the same as those in the semiconductor device 112.

[0057] Also in the semiconductor device 113, in the region overlapping with the second conductive region 61b, the carrier concentration can be locally lowered. A high breakdown voltage can be easily obtained. A semiconductor device with improved characteristics can be provided.

[0058] In the embodiment, information regarding crystallinity is obtained, for example, by an X-ray diffraction pattern image or the like. Information regarding the composition ratio is obtained, for example, by X-ray photoelectron spectroscopy or the like.

[0059] In the semiconductor devices 110 to 113 according to the embodiment, the first nitride member 31 may contain In, Ga, and nitrogen. For example, the first nitride member 31 is Al x3 Ga 1-x3 N (0 ≦ x3 <1), or In y1 Al y2 Ga 1-y1-y2 N (0 <y1 ≦ 1, 0 ≦ y2 ≦ 1, y1 + y2 ≦ 1) may be included. For example, the first nitride member 31 is In y1 Ga 1-y1 N (0 <y1 ≦ 1) may be included. On the other hand, the second nitride member 32 is Al x4 Ga 1-x4It includes N(0 < x4 ≤ 1, x3 < x4). For example, the first nitride member 31 includes InGaN, and the second nitride member 32 includes AlGaN or AlN.

[0060] (Third Embodiment) FIG. 5 is a schematic cross-sectional view illustrating a semiconductor device according to the third embodiment. As shown in FIG. 5, in the semiconductor device 121, the first nitride member 31 includes fourth to seventh nitride regions 31d to 31g in addition to the first to third nitride regions 31a to 31c. The second nitride member 32 includes first to seventh nitride portions 32a to 32g.

[0061] The first nitride portion 32a is between the third portion 22c and the first nitride region 31a. The second nitride portion 32b is between the first portion 22a and the second nitride region 31b. The third nitride portion 32c is between the second portion 22b and the third nitride region 31c.

[0062] The fourth nitride region 31d is between the third partial region 13 and the third electrode 53 in the second direction D2. The fourth nitride region 31d is between the first insulating region 41a and the third electrode 53 in the second direction D2. The fifth nitride region 31e is, for example, between the first semiconductor portion 21 and at least a part of the third electrode 53 in the first direction D1. The fifth nitride region 31e is, for example, between the first semiconductor portion 21 and at least a part of the second insulating region 41b in the first direction D1. The sixth nitride region 31f is, for example, between at least a part of the third electrode 53 and the first portion 22a in the first direction D1. The sixth nitride region 31f is, for example, between at least a part of the third insulating region 41c and the first portion 22a in the first direction D1.

[0063] The fourth nitride portion 32d is between the third partial region 13 and the fourth nitride region 31d in the second direction D2. The fifth nitride portion 32e is between the first semiconductor portion 21 and the fifth nitride region 31e in the second direction D2. The sixth nitride portion 32f is between the sixth nitride region 31f and the first portion 22a in the second direction D2.

[0064] The first semiconductor portion 21 is located between the fourth partial region 14 and the seventh nitride region 31g in the second direction D2. Third insulating portion 42c is located between the seventh nitride portion 32g and the seventh nitride region 31g in the second direction D2.

[0065] The configuration of the semiconductor device 121 other than the above may be the same as that of the semiconductor device 111. By providing the first nitride member 31 and the second nitride member 32 as described above, for example, a lower subthreshold swing can be easily obtained.

[0066] FIG. 6 is a schematic cross-sectional view illustrating a semiconductor device according to the third embodiment. As shown in FIG. 6, in the semiconductor device 122, the first nitride member 31 includes the first to seventh nitride regions 31a to 31g. The second nitride member 32 includes the first to seventh nitride portions 32a to 32g. The configuration of the semiconductor device 122 other than the above may be the same as that of the semiconductor device 112. By providing the first nitride member 31 and the second nitride member 32 as described above, for example, a lower subthreshold swing can be easily obtained.

[0067] In the semiconductor devices 112 and 122 , example For example, the first nitride member 31 contains Al x3 Ga 1-x3 N (0 ≦ x3 < 1), or In y1 Al y2 Ga 1-y1-y2 N (0 < y1 ≦ 1, 0 ≦ y2 ≦ 1, y1 + y2 ≦ 1) may be included. For example, the first nitride member 31 may contain In y1 Ga 1-y1 N (0 < y1 ≦ 1). On the other hand, the second nitride member 32 contains Al x4 Ga 1-x4 N (0 < x4 ≦ 1, x3 < x4). For example, the first nitride member 31 contains InGaN, and the second nitride member 32 contains AlGaN or AlN.

[0068] According to the embodiment, a semiconductor device capable of improving characteristics can be provided.

[0069] In the embodiment, the "nitride semiconductor" is B x In y Al z Ga 1-x-y-z It includes semiconductors of all compositions in which the composition ratios x, y, and z are varied within their respective ranges in the chemical formula N(0≦x≦1, 0≦y≦1, 0≦z≦1, x + y + z≦1). In the above chemical formula, those further containing group V elements other than N (nitrogen), those further containing various elements added to control various physical properties such as conductivity type, and those further containing various elements contained unintentionally are also included in the "nitride semiconductor".

[0070] In the present specification, "vertical" and "parallel" include not only strict vertical and strict parallel, but also, for example, variations in the manufacturing process, and it is sufficient that they are substantially vertical and substantially parallel.

[0071] The embodiments of the present invention have been described above with reference to specific examples. However, the present invention is not limited to these specific examples. For example, regarding the specific configurations of each element such as electrodes, semiconductor members, compound members, nitride members, and insulating members included in the semiconductor device, the present invention can be similarly implemented by appropriately selecting from the ranges 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.

[0072] Also, those obtained by combining any two or more elements of each specific example within a technically possible range are included in the scope of the present invention as long as they include the gist of the present invention.

[0073] In addition, based on the semiconductor device described above as an embodiment of the present invention, all semiconductor devices 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.

[0074] In addition, within the scope of the idea of the present invention, those skilled in the art can conceive of various modification examples and correction examples, and these modification examples and correction examples are also understood to belong to the scope of the present invention.

[0075] Although some embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the gist of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalent scope thereof.

Explanation of Reference Numerals

[0076] 10... First semiconductor region, 10B... Nitride semiconductor layer, 10C... Carrier region, 10M... Semiconductor member, 10s... Substrate, 11 to 15... First to fifth partial regions, 20... Second semiconductor region, 21, 22... First and second semiconductor parts, 22a to 22c... First to third parts, 22p... End, 22q... Portion, 31... First nitride member, 31a to 31g... First to seventh nitride regions, 32... Second nitride member, 32a to 32g... First to seventh nitride parts, 41... First insulating member, 41a to 41f... First to sixth insulating regions, 42... Second insulating member, 42a to 42c... First to third insulating parts, 51 to 53... First to third electrodes, 61... First conductive member, 61a, 61b... First and second conductive regions, 61e... First conductive end portion, 110 to 113, 121, 122... Semiconductor devices, D1, D2... First and second directions, t1, t2... Thicknesses, w1, w2... First and second lengths

Claims

1. a first electrode; a second electrode; a third electrode, wherein a position of the third electrode in a first direction from the first electrode to the second electrode is between a position of the first electrode in the first direction and a position of the second electrode in the first direction, the third electrode; a semiconductor member including a first semiconductor region and a second semiconductor region, The first semiconductor region is Al ｘ１ Ga １－ｘ１ N (0 ≦ x1 < 1), the first semiconductor region includes a first partial region, a second partial region, a third partial region, a fourth partial region, and a fifth 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, a position of the fourth partial region in the first direction is between a position of the first partial region in the first direction and a position of the third partial region in the first direction, and a position of the fifth partial region in the first direction is between the position of the third partial region in the first direction and a position of the second partial region in the first direction. The second semiconductor region is Al ｘ２ Ga １－ｘ２ N (0 < x2 ≤ 1, x1 < x2), the second semiconductor region includes a first semiconductor portion and a second 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 second semiconductor portion includes a first portion, a second portion, and a third portion between the first portion and the second portion, the position of the second portion in the first direction is between the position of the first portion in the first direction and the position of the second electrode in the first direction, the semiconductor member a first conductive member including a first conductive region and a second conductive region, wherein the first conductive region overlaps with the third electrode in a second direction, the first portion is between the fifth partial region and a part of the first conductive region, the first conductive member is electrically connected to one of the first electrode and the third electrode, or the first conductive member can be electrically connected to the one, the first conductive member; a first insulating member including a first insulating region, wherein the first insulating region is between the third partial region and the third electrode in the second direction, the first insulating member; a second insulating member including a first insulating portion and a second insulating portion, wherein the first insulating portion is between the first portion and the first conductive region in the second direction, the second portion is between the fifth partial region and the second insulating portion, the second insulating member; Al ｘ３ Ga １－ｘ３ N (0 ≦ x3 < 1) or In ｙ１ Al ｙ２ Ga １－ｙ１－ｙ２ A first nitride member containing N (0 < y1 ≦ 1, 0 ≦ y2 ≦ 1, y1 + y2 ≦ 1), wherein the first nitride member includes a first nitride region, the first nitride region is between the first insulating portion and the second insulating portion in the first direction, and the first nitride region is between the third portion and the second conductive region in the second direction, the first nitride member, comprising the first nitride member includes a second nitride region and a third nitride region, the first insulating portion is between the first portion and the second nitride region, the second insulating portion is between the second portion and the third nitride region, a semiconductor device.

2. At least a part of the second insulating portion does not overlap with the first conductive member in the second direction, the semiconductor device according to Claim 1.

3. Crystallinity of the first nitride region is higher than crystallinity of the second nitride region and higher than crystallinity of the third nitride region, the semiconductor device according to Claim 1.

4. At least a part of the first nitride region includes crystals, at least a part of the second nitride region is amorphous, at least a part of the third nitride region is amorphous, the semiconductor device according to Claim 1.

5. The first nitride region is in contact with the third portion, the semiconductor device according to any one of Claims 1 to 4.

6. Al ｘ４ Ga １－ｘ４ further includes a second nitride member containing N (0 < x4 ≤ 1, x3 < x4). At least a part of the second nitride member is between the first portion and the first insulating portion and between the second portion and the second insulating portion, the semiconductor device according to any one of Claims 1 to 4.

7. The semiconductor device according to claim 6, wherein a part of the second nitride member is between the third portion and the first nitride region.

8. The semiconductor device according to claim 6 or 7, wherein the second nitride member is in contact with the third portion and the first nitride region.

9. The semiconductor device according to any one of claims 6 to 8, wherein the thickness of the second nitride member along the second direction is 1 nm or more and 10 nm or less.

10. The semiconductor device according to any one of claims 1 to 9, wherein x3 is lower than x2.

11. The semiconductor device according to any one of claims 1 to 9, wherein the thickness of the first nitride region along the second direction is 1 nm or more and 10 nm or less.

12. The semiconductor device according to any one of claims 1 to 11, wherein the second insulating member contains silicon and nitrogen.

13. The first insulating member contains silicon and oxygen, The semiconductor device according to claim 12, wherein the first insulating member does not contain nitrogen, or the concentration of nitrogen in the first insulating member is lower than the concentration of nitrogen in the second insulating member.

14. The first insulating member further includes a second insulating region and a third insulating region, The second insulating region is between the first semiconductor portion and the third electrode in the first direction, The semiconductor device according to any one of claims 1 to 13, wherein the third insulating region is between the third electrode and the second semiconductor portion in the first direction.

15. The first insulating member further includes a fourth insulating region, The semiconductor device according to any one of claims 1 to 14, wherein at least a part of the fourth insulating region is between the third electrode and the first conductive member.

16. A first electrode, A second electrode, A third electrode, wherein the position of the third electrode in the first direction from the first electrode to the second electrode is between the position of the first electrode in the first direction and the position of the second electrode in the first direction, the third electrode, A semiconductor member including a first semiconductor region and a second semiconductor region, The first semiconductor region is Al ｘ１ Ga １－ｘ１ N (0 ≦ x1 < 1), the first semiconductor region includes a first partial region, a second partial region, a third partial region, a fourth partial region, and a fifth partial region, a second direction from the first partial region to the first electrode intersects 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, a position of the fourth partial region in the first direction is between a position of the first partial region in the first direction and a position of the third partial region in the first direction, and a position of the fifth partial region in the first direction is between the position of the third partial region in the first direction and a position of the second partial region in the first direction. The second semiconductor region is Al ｘ２ Ga １－ｘ２ N (0 < x2 ≤ 1, x1 < x2), the second semiconductor region includes a first semiconductor portion and a second 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 second semiconductor portion includes a first portion, a second portion, and a third portion between the first portion and the second portion, and the position of the second portion in the first direction is between the position of the first portion in the first direction and the position of the second electrode in the first direction, the semiconductor member A first conductive member including a first conductive region and a second conductive region, wherein the first conductive region overlaps with the third electrode in the second direction, the first portion is between the fifth partial region and a part of the first conductive region, the first conductive member is electrically connected to one of the first electrode and the third electrode, or the first conductive member can be electrically connected to the one, the first conductive member, A first insulating member including a first insulating region, wherein the first insulating region is between the third partial region and the third electrode in the second direction, the first insulating member, A second insulating member including a first insulating portion and a second insulating portion, wherein the first insulating portion is between the first portion and the first conductive region in the second direction, the second portion is between the fifth partial region and the second insulating portion, the second insulating member, Al ｘ３ Ga １－ｘ３ N (0 ≦ x3 < 1) or In ｙ１ Al ｙ２ Ga １－ｙ１－ｙ２ A first nitride member containing N (0 < y1 ≦ 1, 0 ≦ y2 ≦ 1, y1 + y2 ≦ 1), wherein the first nitride member includes a first nitride region, the first nitride region is between the first insulating portion and the second insulating portion in the first direction, and the first nitride region is between the third portion and the second conductive region in the second direction, the first nitride member, comprising, the first insulating member further includes a fourth insulating region, at least a part of the fourth insulating region is between the third electrode and the first conductive member, a semiconductor device.

17. At least a part of the first insulating region is between the fourth partial region and the fifth partial region in the first direction, the semiconductor device according to any one of claims 1 to 16.

18. At least a part of the third electrode is between the first semiconductor portion and the second semiconductor portion in the first direction, the semiconductor device according to any one of claims 1 to 17.

19. The distance along the first direction between the first electrode and the third electrode is shorter than the distance along the first direction between the third electrode and the second electrode, the semiconductor device according to any one of claims 1 to 18.

20. The first length along the first direction of the first nitride region is not less than 0.035 times and not more than 0.5 times the second length, the second length is the distance in the first direction between the end of the third electrode side of the second semiconductor portion and the position of the portion overlapping with the second electrode of the second semiconductor portion in the second direction, the semiconductor device according to any one of claims 1 to 19.

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