Semiconductor device

Abstract

The present invention provides a semiconductor device that makes it possible to improve withstand voltage. A semiconductor device according to one embodiment comprises first to third electrodes and first and second semiconductor parts. The first semiconductor part is of a first conductivity type. The first semiconductor part includes first to third semiconductor regions. The concentration of impurities of the first conductivity type in the second and third semiconductor regions is higher than the concentration of impurities of the first conductivity type in the first semiconductor region. The second semiconductor part includes first to fourth portions. The first to third portions are provided to a cell part. The first portion and the third portion have a first depth. The second portion is provided between the first portion and the third portion. The second portion has a second depth which is shallower than the first depth. The first portion is provided on the second semiconductor region. The fourth portion is provided on the third semiconductor region.

Description

Semiconductor Devices

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

[0002] In semiconductor devices, there is a demand for improved breakdown voltage.

[0003] JP 2023-45865 A

[0004] The embodiments of the present invention provide a semiconductor device capable of improving the breakdown voltage.

[0005] According to an embodiment, a semiconductor device includes a first electrode, a second electrode, a third electrode, a first semiconductor portion, a second semiconductor portion, a third semiconductor portion, and a fourth semiconductor portion. The first semiconductor portion is provided between the first electrode and the second electrode and is of a first conductivity type. The first semiconductor portion includes a first semiconductor region, a second semiconductor region provided on the first semiconductor region in a first direction from the first electrode to the second electrode that intersects with a second direction from the cell portion to the terminal portion and in the cell portion, the second semiconductor region having a higher impurity concentration of the first conductivity type than the impurity concentration of the first conductivity type in the first semiconductor region, and a third semiconductor region provided on the first semiconductor region in the first direction and in the terminal portion, the third semiconductor region having a higher impurity concentration of the first conductivity type than the impurity concentration of the first conductivity type in the first semiconductor region. The second semiconductor portion is of a second conductivity type and provided on the first semiconductor portion. In the cell section, the second semiconductor portion has a first portion with a first depth, a second portion with a second depth shallower than the first depth, and a third portion with the first depth. The first portion, the second portion, and the third portion are provided on the second semiconductor region such that the second portion is provided between the first portion and the third portion. In the termination section, a fourth portion is provided on the third semiconductor region. The third semiconductor portion is of the second conductivity type. The third semiconductor portion has a first region portion provided on the first portion, the second portion, and the third portion, and a second region portion provided on the fourth portion. The fourth semiconductor portion is of the first conductivity type. The fourth semiconductor portion is provided on the first portion, the first region portion, and the third portion. The third electrode is provided between the first portion and the second electrode.

[0006] FIG. 1 is a schematic cross-sectional view illustrating a semiconductor device according to a first embodiment; FIG. 2 is a schematic view illustrating characteristics of the semiconductor device according to the first embodiment; FIG. 3 is a schematic cross-sectional view illustrating a semiconductor device according to a comparative example; FIG. 4 is a schematic view illustrating characteristics of the semiconductor device according to the comparative example; FIG. 5 is a schematic cross-sectional view illustrating a semiconductor device according to the first embodiment; FIG. 6 is a schematic cross-sectional view illustrating a semiconductor device according to a second embodiment; and FIG. 7 is a schematic cross-sectional view illustrating a semiconductor device according to a third embodiment.

[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 may be different depending on the drawing. In this specification and each drawing, elements similar to those previously described with reference to the previous drawings are designated by the same reference numerals, and detailed descriptions will be omitted as appropriate.

[0008] First Embodiment FIG. 1 is a schematic cross-sectional view illustrating a semiconductor device according to a first embodiment. As shown in FIG. 1, a semiconductor device 100 according to the embodiment includes a first electrode 51, a second electrode 52, a third electrode 53, a first semiconductor portion 11, a second semiconductor portion 12, a third semiconductor portion 13, and a fourth semiconductor portion 14. The first semiconductor portion 11, the second semiconductor portion 12, the third semiconductor portion 13, and the fourth semiconductor portion 14 include SiC. The first semiconductor portion 11, the second semiconductor portion 12, the third semiconductor portion 13, and the fourth semiconductor portion 14 may include at least one selected from the group consisting of 4H—SiC, 6H—SiC, and 3C—SiC. These semiconductor portions include crystals. These semiconductor portions may include silicon. These semiconductor portions may include a compound semiconductor including Ga.

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

[0010] 1 , the semiconductor device 100 includes a cell portion 110, a termination portion 120, and a connection portion 130. The connection portion 130 is provided between the cell portion 110 and the termination portion 120. For example, the cell portion 110, the termination portion 120, and the connection portion 130 may be defined for the first semiconductor portion 11.

[0011] The first semiconductor portion 11 is of a first conductivity type. The second semiconductor portion 12 is of a second conductivity type. The first conductivity type is one of n-type and p-type. The second conductivity type is the other of n-type and p-type. In the following, the first conductivity type is n-type, and the second conductivity type is p-type.

[0012] The first semiconductor part 11 is provided between the first electrode 51 and the second electrode 52. The first semiconductor part 11 includes a cell part 110, a connection part 130, and a termination part 120. The first semiconductor part 11 includes a first semiconductor region 11a, a second semiconductor region 11b, and a third semiconductor region 11c.

[0013] The second semiconductor region 11b is provided on the first semiconductor region 11a in the X-axis direction (first direction) from the first electrode 51 to the second electrode 52, which intersects with the Z-axis direction (second direction) from the cell portion 110 to the termination portion 120, and in the cell portion 110.

[0014] The third semiconductor region 11c is provided on the first semiconductor region 11a in the Z-axis direction and in the termination portion 120.

[0015] The impurity concentrations of the first conductivity type in the second semiconductor region 11b and the third semiconductor region 11c are higher than the impurity concentration in the first semiconductor region 11a. The first semiconductor region 11a is, for example, an n-type region. The second semiconductor region 11b and the third semiconductor region 11c are, for example, n-type regions. ＋ The boundaries between the first semiconductor region 11a, the second semiconductor region 11b, and the third semiconductor region 11c may be clear or unclear.

[0016] In the cell portion 110, the second semiconductor portion 12 has a first portion 12a having a first depth, a second portion 12b having a second depth shallower than the first depth, and a third portion 12c having the first depth. The second portion 12b is provided between the first portion 12a and the third portion 12c. The first portion 12a, the second portion 12b, and the third portion 12c are provided on the second semiconductor region 11b. In the termination portion 120, a part of a fourth portion 12d is provided on the third semiconductor region 11c. The depth of the fourth portion 12d is a second depth shallower than the first depth. Here, the depth corresponds to, for example, a position in the X-axis direction (first direction) based on the position of the first electrode 51 in the first direction. The distance between the first electrode 51 and the first portion 12a in the first direction is shorter than the distance between the first electrode 51 and the second portion 12b in the first direction. The distance along the first direction between the first electrode 51 and the third portion 12c is shorter than the distance along the first direction between the first electrode 51 and the second portion 12b. The distance along the first direction between the first electrode 51 and the fourth portion 12d is longer than the distance along the first direction between the first electrode 51 and the first portion 12a. The distance along the first direction between the first electrode 51 and the fourth portion 12d is longer than the distance along the first direction between the first electrode 51 and the third portion 12c. In one example, the length along the second direction of the fourth portion 12d may be longer than the length along the second direction of the third portion 12c.

[0017] The boundaries between the first portion 12 a, the second portion 12 b, the third portion 12 c, and the fourth portion 12 d may be clear or unclear. The first portion 12 a, the second portion 12 b, the third portion 12 c, and the fourth portion 12 d are semiconductor regions that represent portions of the second semiconductor portion 12.

[0018] In the termination portion 120, a third semiconductor region 11c is provided on the side surface and bottom surface of the fourth portion 12d. In the termination portion 120, a portion of the third semiconductor region 11c is electrically connected to the second electrode 52. For example, the distance in the first direction between the first electrode 51 and the third semiconductor region 11c is longer than the distance in the first direction between the first electrode 51 and the third portion 12c. For example, the distance in the first direction between the first electrode 51 and the third semiconductor region 11c is shorter than the distance in the first direction between the first electrode 51 and the fourth portion 12d. For example, the distance in the first direction between the first electrode 51 and the third semiconductor region 11c is longer than the distance in the first direction between the first electrode 51 and the second semiconductor region 11b.

[0019] The third semiconductor portion 13 is of the second conductivity type. The impurity concentration of the second conductivity type in the third semiconductor portion 13 is higher than the impurity concentration of the second conductivity type in the second semiconductor portion 12. The third semiconductor portion 13 is, for example, p ＋＋ The third semiconductor portion 13 includes a first region portion 13a and a second region portion 13b. The first region portion 13a is provided on the first portion 12a, the second portion 12b, and the third portion 12c. A portion of the first region portion 13a is electrically connected to the second electrode 52. For example, the first region portion 13a is in ohmic contact with the second electrode 52. The second region portion 13b is provided on the fourth portion 12d in the termination portion 120. The boundary between the first region portion 13a and the second region portion 13b may be clear or unclear. The first region portion 13a and the second region portion 13b are each semiconductor regions that represent a portion of the third semiconductor portion 13.

[0020] The fourth semiconductor portion 14 is of the first conductivity type. The impurity concentration of the first conductivity type in the fourth semiconductor portion 14 is higher than the impurity concentration of the first conductivity type in the first semiconductor portion 11. The fourth semiconductor portion 14 is, for example, n ＋＋The fourth semiconductor portion 14 is a region. The fourth semiconductor portion 14 is provided on the first portion 12a, the first region portion 13a, and the second portion 12b. The fourth semiconductor portion 14 includes a first region 14a and a second region 14b. The first region 14a is provided on the first portion 12a. The second region 14b is provided on the second portion 12b. A portion of the fourth semiconductor portion 14 is electrically connected to the second electrode 52. For example, the fourth semiconductor portion 14 is in ohmic contact with the second electrode 52. The boundary between the first region 14a and the second region 14b may be clear or unclear. The first region 14a and the second region 14b are each semiconductor regions that represent a portion of the fourth semiconductor portion 14.

[0021] A first insulating portion 41 is provided around the third electrode 53. A part of the first insulating portion 41 is provided between the second semiconductor region 11b and the third electrode 53. The first insulating portion 41 is made of, for example, SiO ２ The semiconductor device 100 may also be provided with insulating portions 15. The insulating portions 15 are provided between the fourth semiconductor portion 14 and the second electrode 52, between the fourth portion 12 d and the second electrode 52, and between the fourth portion 12 d and the second electrode 52.

[0022] 1 , the fifth semiconductor portion 16 is provided between the first electrode 51 and the first semiconductor portion 11 in the first direction. The impurity concentration of the first conductivity type in the fifth semiconductor portion 16 is higher than the first impurity concentration in the first semiconductor portion 11. The fifth semiconductor portion 16 may correspond to, for example, at least one of a buffer layer and a substrate. A low-resistance electrical connection is obtained.

[0023] 1 , the semiconductor device 100 may be provided with a first silicide 17a and a second silicide 17b. The first silicide 17a is provided in the cell portion 110. The first silicide 17a is provided between the first region portion 13a and the second electrode 52 in the first direction. At least a portion of the first silicide 17a is provided between the first region 14a and the second region 14b in the second direction. The second silicide 17b is provided in the termination portion 120. The second silicide 17b is provided between the second region portion 13b and the second electrode 52 in the first direction.

[0024] In the semiconductor device 100, 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 second electrode 52. 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 100 is, for example, a transistor. Furthermore, the semiconductor device 100 is, for example, a MOSFET (Metal-Oxide-Semiconductor Field Effect Transistor) with a built-in Schottky barrier diode.

[0025] 2 is a schematic diagram illustrating the characteristics of the semiconductor device 100. The first electrode 51 and the fifth semiconductor portion 16 are omitted from FIG. 2. In FIG. 2, the electric field is high in the dark areas and low in the light areas. In addition, in the cell portion 110, a current E flows in the Y-axis direction through the second portion 12b.

[0026] 3 is a schematic cross-sectional view illustrating a semiconductor device 100A according to a comparative example. In FIG. 3, the same components as those in the semiconductor device 100 are denoted by the same reference numerals. In the semiconductor device 100A, a fourth semiconductor region 11d, in which the second semiconductor region 11b of the cell unit 110 and the third semiconductor region 11c of the termination unit 120 are connected, is provided on the first semiconductor region 11a. The fourth semiconductor region 11d is of n-type. The impurity concentration of the first conductivity type in the fourth semiconductor region 11d is higher than the impurity concentration in the first semiconductor region 11a.

[0027] 4 is a schematic diagram illustrating the characteristics of the semiconductor device 100A in the comparative example. In FIG. 4, the electric field is high in the dark areas and low in the light areas. In addition, in the termination portion 120, a current E flows in the Y-axis direction through the end of the fourth portion 12d.

[0028] As shown in FIG. 4 , if a fourth semiconductor region 11d is provided from the cell unit 110 through the connection unit 130 to the termination unit 120, the electric field will be stronger in the termination unit 120, lowering the breakdown voltage of the semiconductor device 100A. In contrast, as shown in FIG. 2 , in the semiconductor device 100 of this embodiment, the second semiconductor region 11b of the cell unit 110 and the third semiconductor region 11c of the termination unit 120 are spaced apart in the X-axis direction. This allows the electric field to be strengthened in the first portion 12a and the second portion 12b. Therefore, from the cell unit 110 to the termination unit 120, the electric field distribution shown in FIG. 2 is more relaxed than the electric field distribution shown in FIG. 4 . This allows the breakdown voltage of the semiconductor device 100 to be improved.

[0029] 5 is a diagram showing an example of the breakdown voltage of the semiconductor device 100. The horizontal axis of FIG. 5 represents the drain voltage, and the vertical axis represents the drain current. In the semiconductor device 100, the breakdown voltage exceeds a target voltage value T. The voltage value T is, for example, 1600 V.

[0030] A second semiconductor region 11b and a third semiconductor region 11c are provided in the semiconductor device 100. The second semiconductor region 11b and the third semiconductor region 11c each serve as a current spreading layer.

[0031] In the cell region 110, the first portion 12a and the third portion 12c having a first depth are provided on the second semiconductor region 11b. For example, the electric field in the first portion 12a and the third portion 12c can be made stronger in the second semiconductor region 11b. This can alleviate the electric field from the cell region 110 to the termination region 120, thereby improving the breakdown voltage of the semiconductor device 100.

[0032] In the termination unit 120, the third semiconductor region 11c makes Schottky contact with the second electrode 52. A Schottky barrier diode (SBD) is formed in the region including the third semiconductor region 11c, the second electrode 52, and the contact region. This makes it possible to control the operation of the parasitic diode in the termination unit 120. Increasing the contact region makes it possible to increase the unipolar current.

[0033] Second Embodiment The second embodiment differs from the first embodiment in that a fifth portion 12 e is provided. Therefore, the differences resulting from the provision of the fifth portion 12 e will be described. Note that the same components as those in the first embodiment are designated by the same reference numerals, and detailed descriptions thereof will be omitted.

[0034] 6 is a schematic cross-sectional view illustrating a semiconductor device according to the second embodiment. As shown in FIG. 6, in the semiconductor device 200 according to the embodiment, the second semiconductor portion 12 includes a fifth portion 12 e in the connection portion 130. The configuration of the semiconductor device 200 other than this may be similar to that of the semiconductor device 100.

[0035] The depth of the fifth portion 12e in the first direction is a third depth. The third depth is deeper than the first depths of the first portion 12a and the third portion 12c. In this example, the position (depth) of the lower end of the fifth portion 12e is substantially the same as the position (depth) of the lower end of the second semiconductor region 11b. The distance in the first direction between the first electrode 51 and the fifth portion 12e is longer than the distance in the first direction between the first electrode 51 and the third portion 12c.

[0036] In the semiconductor device 200, the fifth portion 12e can further reduce the electric field at the end of the third portion 12c, thereby further improving the breakdown voltage of the semiconductor device 200.

[0037] 7 is a schematic cross-sectional view illustrating a semiconductor device according to a third embodiment. As shown in FIG. 7, in a semiconductor device 300 according to the embodiment, the configurations of the cell unit 110 and the connection unit 130 are different from those of the semiconductor device 100. Except for this, the configuration of the semiconductor device 300 may be the same as the configuration of the semiconductor device 100 or the semiconductor device 200.

[0038] In the semiconductor device 300, in the cell section 110, the third portion 12c extends toward the connection section 130. The second region 14b on the second portion 12b also extends toward the connection section 130.

[0039] A gap S2 is provided in the second semiconductor portion 12. The gap S2 is provided at the connection portion between the cell portion 110 and the connection portion 130. The width W1 of the gap S2 is, for example, not less than 0.1 μm and not more than 10 μm. The width W1 may be, for example, 1 μm. The depth of the lower end of the second semiconductor portion 12 corresponding to the gap S2 may be substantially the same as the depth of the lower end of the third semiconductor portion 13, for example.

[0040] In the semiconductor device 300, the fifth portion 12e includes the gap S2. By providing the gap S2, the electric field can be further alleviated compared to the semiconductor device 200 of the second embodiment. The semiconductor device 300 can further improve the breakdown voltage.

[0041] In the embodiment, for example, the impurities of the first conductivity type include at least one selected from the group consisting of N, P, and As. For example, the impurities of the second conductivity type include at least one selected from the group consisting of B, Al, and Ga.

[0042] In one example, the concentration of the first conductivity type impurity in the first semiconductor portion 11 is, for example, 1×10 １４ cm －３ 1x10 or more １７ cm －３ In one example, the concentration of the second conductivity type impurity in the second semiconductor portion 12 is, for example, 1×10 １６ cm －３ 1x10 or more ２０ cm －３ In one example, the concentration of the second conductivity type impurity in the third semiconductor portion 13 is, for example, 1×10 １９ cm －３ 1x10 or more ２１ cm －３ In one example, the concentration of the impurity of the first conductivity type in the fourth semiconductor portion 14 is, for example, 1×10 １９ cm －３ 1x10 or more ２１ cm －３ In one example, the concentration of the impurity of the first conductivity type in the fifth semiconductor portion 16 is, for example, 1×10 １５ cm －３ 1x10 or more １８ cm －３The above impurity concentration may be, for example, a substantial carrier concentration.

[0043] In an embodiment, information about the length and thickness can be obtained by electron microscopy, etc. Information about the material composition can be obtained by SIMS (Secondary Ion Mass Spectrometry) or EDX (Energy Dispersive X-ray spectroscopy), etc.

[0044] The embodiments include the following aspects.

[0045] (Supplementary Note 1) A first electrode; a second electrode; a first semiconductor part of a first conductivity type provided between the first electrode and the second electrode, the first semiconductor part having: a first semiconductor region; a second semiconductor region provided on the first semiconductor region in a first direction from the first electrode to the second electrode intersecting a second direction from the cell part to the termination part, and in the cell part, the second semiconductor region having a higher impurity concentration of the first conductivity type than the impurity concentration of the first conductivity type in the first semiconductor region; and a third semiconductor region provided on the first semiconductor region in the first direction and in the termination part, the third semiconductor region having a higher impurity concentration of the first conductivity type than the impurity concentration of the first conductivity type in the first semiconductor region; and a second semiconductor part of a second conductivity type provided on the first semiconductor part, the second semiconductor part having: in the cell part, a first portion of a first depth; a second portion of a second depth shallower than the first depth; the first portion, the second portion, and the third portion are provided on the second semiconductor region so that the second portion is provided between the first portion and the third portion, and at the termination portion, a fourth portion is provided on the third semiconductor region; a third semiconductor portion of the second conductivity type, the third semiconductor portion having a first region portion provided on the first portion, the second portion, and the third portion, and a second region portion provided on the fourth portion; a fourth semiconductor portion of the first conductivity type provided on the first portion, the first region portion, and the third portion; and a third electrode provided between the first portion and the second electrode.

[0046] (Supplementary Note 2) The semiconductor device according to Supplementary Note 1, wherein the third semiconductor region and the second electrode are in Schottky contact.

[0047] (Supplementary Note 3) The semiconductor device described in Supplementary Note 1 or 2 further comprises a connection portion provided between the cell portion and the termination portion in the second direction, wherein the second semiconductor portion further includes a fifth portion, wherein the fifth portion is provided on the first semiconductor region in the connection portion, and at least a portion of the fifth portion has a third depth that is deeper than the first depth.

[0048] (Supplementary Note 4) The semiconductor device according to Supplementary Note 3, wherein the fifth portion includes a gap.

[0049] (Supplementary Note 5) The semiconductor device according to any one of Supplementary Notes 1 to 4, further comprising a first insulating portion, at least a portion of the first insulating portion being provided between the first portion and the third electrode.

[0050] (Appendix 6) A semiconductor device according to any one of Appendices 1 to 5, wherein the impurity concentration of the first conductivity type in the fourth semiconductor portion is higher than the impurity concentration of the first conductivity type in the first semiconductor portion, and the impurity concentration of the second conductivity type in the third semiconductor portion is higher than the impurity concentration of the second conductivity type in the second semiconductor portion.

[0051] (Supplementary Note 7) The semiconductor device according to any one of Supplementary Notes 1 to 6, wherein a part of the third semiconductor portion and a part of the fourth semiconductor portion are in ohmic contact with the second electrode.

[0052] (Appendix 8) The semiconductor device according to any one of appendices 1 to 7, wherein the cell portion comprises a silicide, the silicide being provided between the first region portion and the second electrode in the first direction, and at least a portion of the silicide being provided between the first region and the second region in the second direction.

[0053] (Appendix 9) The semiconductor device according to any one of Appendices 1 to 8, further comprising a fifth semiconductor portion of the first conductivity type, the fifth semiconductor portion being provided between the first electrode and the first semiconductor portion in the first direction, and the impurity concentration of the first conductivity type in the fifth semiconductor portion being higher than the impurity concentration of the first conductivity type in the first semiconductor portion.

[0054] (Supplementary Note 10) The semiconductor device according to any one of Supplementary Notes 1 to 9, wherein the first depth and the second depth correspond to positions in the first direction based on the position of the first electrode in the first direction.

[0055] (Supplementary Note 11) The semiconductor device according to any one of Supplementary Notes 1 to 10, wherein the first semiconductor portion, the second semiconductor portion, the third semiconductor portion, and the fourth semiconductor portion include SiC.

[0056] According to the embodiment, a semiconductor device capable of improving the breakdown voltage is provided.

[0057] The embodiments of the present invention have been described above with reference to specific examples. However, the present invention is not limited to these specific examples. For example, the specific configurations of the elements included in the semiconductor device, such as the electrodes, semiconductor portion, and insulating portion, are within the scope of the present invention as long as a person skilled in the art can implement the present invention in a similar manner and obtain similar effects by appropriately selecting them from known ranges.

[0058] Furthermore, any combination of two or more elements of each specific example within the scope of technical feasibility is also included within the scope of the present invention as long as it includes the gist of the present invention.

[0059] In addition, all semiconductor devices that can be implemented by a person skilled in the art by appropriately modifying the design based on the semiconductor device described above as an embodiment of the present invention also fall within the scope of the present invention as long as they include the gist of the present invention.

[0060] In addition, within the scope of the concept of the present invention, a person skilled in the art may come up with various modifications and alterations, and it will be understood that these modifications and alterations also fall within the scope of the present invention.

[0061] Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, and are also included in the scope of the invention and its equivalents as defined in the claims.

[0062] 11 to 14...first to fourth semiconductor portions, 11a to 11c...first to third semiconductor regions, 12a to 12e...first to fifth portions, 13a, 13b...first and second region portions, 14a, 14b...first and second regions, 15...insulating portion, 16...fifth semiconductor portion, 17a, 17b...first and second silicide layers, 41...first insulating portion, 51 to 53...first to third electrodes, 100, 200, 300...semiconductor device, 110...cell portion, 120...termination portion, 130...connection portion, S2...gap, W1...width

Claims

1. A first electrode; a second electrode; and a first semiconductor portion of a first conductivity type provided between the first electrode and the second electrode, the first semiconductor portion having: a first semiconductor region; a second semiconductor region provided on the first semiconductor region in a first direction from the first electrode to the second electrode intersecting a second direction from the cell portion to the terminal portion, and in the cell portion, the second semiconductor region having a higher impurity concentration of the first conductivity type than the impurity concentration of the first conductivity type in the first semiconductor region; and a third semiconductor region provided on the first semiconductor region in the first direction and in the terminal portion, the third semiconductor region having a higher impurity concentration of the first conductivity type than the impurity concentration of the first conductivity type in the first semiconductor region; and a second semiconductor portion of a second conductivity type provided on the first semiconductor portion, the second semiconductor portion having: a first portion of a first depth, a second portion of a second depth shallower than the first depth, and a third portion of the first depth, a fourth semiconductor portion having a first region portion provided on the first portion, the second portion, and the third portion such that the second portion is provided between the first portion and the third portion, and at the termination portion, a fourth portion being provided on the third semiconductor region; a third semiconductor portion of the second conductivity type, the third semiconductor portion having a first region portion provided on the first portion, the second portion, and the third portion, and a second region portion provided on the fourth portion; a fourth semiconductor portion of the first conductivity type provided on the first portion, the first region portion, and the third portion; and a third electrode provided between the first portion and the second electrode.

2. The semiconductor device according to claim 1, wherein said third semiconductor region and said second electrode are in Schottky contact.

3. The semiconductor device according to claim 2, further comprising a connection portion provided between the cell portion and the termination portion in the second direction, the second semiconductor portion further including a fifth portion, the fifth portion being provided on the first semiconductor region at the connection portion, and at least a portion of the fifth portion having a third depth deeper than the first depth.

4. The semiconductor device according to claim 3, wherein the fifth portion includes a gap.

5. The semiconductor device according to claim 1, further comprising a first insulating portion, at least a portion of said first insulating portion being provided between said first portion and said third electrode.

6. The semiconductor device described in claim 1, wherein an impurity concentration of the first conductivity type in the fourth semiconductor portion is higher than an impurity concentration of the first conductivity type in the first semiconductor portion, and an impurity concentration of the second conductivity type in the third semiconductor portion is higher than an impurity concentration of the second conductivity type in the second semiconductor portion.

7. The semiconductor device according to claim 1, wherein a portion of said third semiconductor portion and a portion of said fourth semiconductor portion are in ohmic contact with said second electrode.

8. The semiconductor device according to claim 1, wherein the first depth and the second depth correspond to positions in the first direction based on the position of the first electrode in the first direction.

9. The semiconductor device according to claim 1, wherein the first semiconductor portion, the second semiconductor portion, the third semiconductor portion and the fourth semiconductor portion comprise SiC.

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