Insulated Gate Bipolar Transistor

Abstract

The present invention provides an insulated gate bipolar transistor. The transistor comprises: an epitaxial layer; a drift region formed in the epitaxial layer, the drift region having a first doping type; a plurality of super junctions formed in the drift region and spaced along a first direction, each super junction extending along a second direction and a third direction, the first direction being parallel to the first surface, the second direction being the direction from the first surface of the drift region to the second surface, the third direction being parallel to the first surface and different from the first direction, the super junction having a second doping type; a collector region formed on the second surface in the epitaxial layer, the collector region having a second doping type; a plurality of short-circuit regions formed on the second surface and spaced along the third direction, the projection of the super junction on the second surface partially overlaps with the projection of at least one short-circuit region on the second surface, and the short-circuit region has the first doping type, and the doping concentration of the short-circuit region is greater than the doping concentration of the drift region. The above-mentioned device has high working stability and reliability.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor technology, and in particular to an insulated gate bipolar transistor. Background Art

[0002] Insulated Gate Bipolar Transistor (IGBT) is a composite fully controlled voltage-driven power semiconductor device composed of a bipolar junction transistor (BJT) and an insulated gate field effect transistor (MOS). It is very suitable for use in power conversion systems with a DC voltage of 600V and above, such as AC motors, inverters, switching power supplies, lighting circuits, and traction.

[0003] In many applications, IGBT needs to be connected in anti-parallel with a diode to achieve freewheeling. The reverse-conducting insulated gate bipolar transistor (RC-IGBT) integrates the IGBT and the diode on the same chip, so that the device has both forward and reverse conduction capabilities, and can improve the integration of the device and save manufacturing costs. However, during the forward conduction process of the RC-IGBT device, its conduction mode will undergo a process of conversion from single-electron conduction to bipolar conduction. When the RC-IGBT switches between the two conduction modes, the current continues to increase while the voltage decreases. This phenomenon is called the negative resistance phenomenon. This phenomenon will cause uneven current distribution in the device, causing some devices to burn out due to excessive current, and some devices to be difficult to start working due to too small current. Summary of the invention

[0004] The main purpose of the present invention is to provide an insulated gate bipolar transistor to solve the problem of uneven current distribution in the prior art.

[0005] In order to achieve the above-mentioned purpose, an insulated gate bipolar transistor is provided, which includes: an epitaxial layer; a drift region formed in the epitaxial layer, the drift region having a first surface and a second surface relative to each other, and the drift region having a first doping type; a plurality of super junctions formed in the drift region and spaced apart along a first direction, each super junction extending along a second direction and a third direction, the first direction being parallel to the first surface, the second direction being a direction from the first surface to the second surface, the third direction being parallel to the first surface and different from the first direction, and the super junction having a second doping type; a collector region formed on the second surface in the epitaxial layer, the collector region having a second doping type; a plurality of short-circuit regions formed on the second surface and spaced apart along the third direction, the projection of each super junction on the second surface partially overlapping with the projection of at least one short-circuit region on the second surface, the short-circuit region having the first doping type, and the doping concentration of the short-circuit region being greater than the doping concentration of the drift region.

[0006] Further, the plurality of super junctions include a plurality of super junction units, each super junction unit includes a plurality of super junctions, and a projection of each super junction unit on the second surface partially overlaps with a projection of the plurality of short-circuit regions on the second surface.

[0007] Furthermore, the super junction unit includes a first super junction unit and a second super junction unit, the first super junction unit and the second super junction unit are alternately arranged along a first direction, the number of super junctions in the first super junction unit is less than the number of super junctions in the second super junction unit, the first super junction unit has a first projection on the second surface, the second super junction unit has a second projection on the second surface, and the first projection and the second projection partially overlap with the projections of the same number of short-circuit areas on the second surface.

[0008] Further, the multiple short-circuit zones include a first short-circuit zone unit and a second short-circuit zone unit, the number of short-circuit zones in the first short-circuit zone unit is greater than the number of short-circuit zones in the second short-circuit zone unit, the first short-circuit zone unit has a third projection on the first surface, the second short-circuit zone unit has a fourth projection on the first surface, the first projection and the third projection partially overlap, and the second projection and the fourth projection partially overlap.

[0009] Further, in the third direction, adjacent short-circuit areas in the first short-circuit area unit have the same first interval, and adjacent short-circuit areas in the second short-circuit area unit have the same second interval, and the first interval is equal to the second interval.

[0010] Further, each third projection overlaps after extending along the first direction, and each third projection does not overlap with the fourth projection after extending along the first direction.

[0011] Furthermore, in the third direction, each first projection has a first area respectively located on both sides of the third projection, each second projection has a plurality of second areas located between adjacent fourth projections, and the area of ​​each first area is equal to that of each second area; in the first direction, the first area does not overlap with the second area after being extended.

[0012] Furthermore, the projected areas of the super junctions on the first surface are equal, and the projected areas of the short-circuit regions on the first surface are equal.

[0013] Furthermore, adjacent super junctions are arranged at equal intervals along the first direction.

[0014] Furthermore, the first direction is perpendicular to the third direction.

[0015] By applying the technical solution of the present invention, an insulated gate bipolar transistor is provided, which includes: an epitaxial layer; a drift region formed in the epitaxial layer, the drift region having a first surface and a second surface opposite to each other, and the drift region having a first doping type; a plurality of super junctions formed in the drift region and spaced along a first direction, each super junction extending along a second direction and a third direction, the first direction being parallel to the first surface, the second direction being a direction from the first surface to the second surface and being perpendicular to the second direction, the third direction being parallel to the first surface and different from the first direction, and the super junction having a second doping type; a collector region formed on the second surface in the epitaxial layer, the collector region having a second doping type; a plurality of short-circuit regions formed on the second surface and spaced along the third direction, the projection of each super junction on the second surface partially overlapping with the projection of at least one short-circuit region on the second surface, the short-circuit region having the first doping type, and the doping concentration of the short-circuit region being greater than the doping concentration of the drift region. By setting a plurality of short-circuit areas at intervals in the above-mentioned insulated gate bipolar transistor, the self-bias effect formed by the initial electron flow in the area with uneven short-circuit areas in the above-mentioned device is very significant, so that the area with uneven short-circuit areas will first enter the bipolar conduction mode and produce a clamping effect. Then, as the current increases, the lateral component of the electron flow in the bipolar conduction area also increases, which will continuously trigger the bipolar conduction of the surrounding short-circuit areas, thereby ensuring that the bipolar current quickly and smoothly transitions from the area with uneven short-circuit areas to the short-circuit area when the device is turned on, so that the current distribution in the device is uniform, the rebound phenomenon is greatly weakened, and the stability and reliability of the device operation are improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the accompanying drawings:

[0017] Figure 1 A schematic cross-sectional structure diagram of an insulated gate bipolar transistor according to an embodiment of the present invention is shown;

[0018] Figure 2 Shows Figure 1 A schematic cross-sectional view of a short-circuit region;

[0019] Figure 3 Shows Figure 2 A cross-sectional schematic diagram of the short-circuit region current is shown;

[0020] Figure 4 Shows Figure 1 A schematic cross-sectional view of the guide IGBT region is shown in FIG.

[0021] The above drawings include the following reference numerals:

[0022] 1. Collector region; 2. Drift region; 3. Super junction; 4. Epitaxial layer; 5. Gate oxide layer; 6. Gate; 7. Doped well; 8. Emitter region; 9. Dielectric layer; 10. Emitter metal; 11. Collector; 12. Collector metal; 13. Short-circuit region; 14. First super junction unit; 15. Second super junction unit; 16. First short-circuit region unit; 17. Second short-circuit region unit; 18. First region; 19. Second region. DETAILED DESCRIPTION

[0023] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0024] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0025] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so as to describe the embodiments of the present invention described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0026] As mentioned in the background technology, during the forward conduction process of the RC-IGBT device, its conduction mode will undergo a process of conversion from single-electron conduction to bipolar conduction. When the RC-IGBT switches between the two conduction modes, the current will continue to increase while the voltage will decrease. This phenomenon is called negative resistance. This phenomenon will cause uneven current distribution in the device, resulting in some devices being burned due to excessive current, and some devices being difficult to start working due to too little current.

[0027] In order to solve the above technical problems, the inventor of the present application proposes an insulated gate bipolar transistor, such as Figure 1As shown, the transistor includes: an epitaxial layer 4; a drift region 2, formed in the epitaxial layer 4, the drift region 2 has a first surface and a second surface opposite to each other, and the drift region 2 has a first doping type; a plurality of super junctions 3, formed in the drift region 2 and spaced along a first direction A, each super junction 3 extends along a second direction B and a third direction C, the second direction B is a direction from the first surface to the second surface, the first direction A is parallel to the first surface, the third direction C is parallel to the first surface and different from the first direction A, and the super junction 3 has a second doping type; a collector region 1, formed on the second surface in the epitaxial layer 4, the collector region 1 has a second doping type; a plurality of short-circuit regions 13, formed on the second surface and spaced along the third direction C, the projection of each super junction on the second surface partially overlaps with the projection of at least one short-circuit region 13 on the second surface, and the short-circuit region 13 has the first doping type, and the doping concentration of the short-circuit region 13 is greater than the doping concentration of the drift region 2.

[0028] In the above-mentioned insulated gate bipolar transistor device, a plurality of short-circuit regions 13 are arranged at intervals on the second surface of the drift region 2, so that in the region where the short-circuit regions 13 are unevenly present in the above-mentioned device, the self-bias effect formed by the initial electron flow is very significant, so that the region where the short-circuit regions 13 are unevenly present will first enter the bipolar conduction mode and produce a clamping effect, and then as the current increases, the lateral component of the electron flow in the bipolar conduction region also increases, which will continuously trigger the bipolar conduction of the surrounding short-circuit regions 13, thereby ensuring that the bipolar current quickly and smoothly transitions from the region where the short-circuit regions 13 are unevenly present to the short-circuit region 13 when the device is turned on, so that the current distribution in the device is uniform, the rebound phenomenon is greatly weakened, and the stability and reliability of the device operation are improved.

[0029] like Figure 1As shown, the device further includes an epitaxial layer 4 , a gate oxide layer 5 , at least one gate 6 , at least one doped well 7 , at least one emitter region 8 , at least one dielectric layer 9 and an emitter metal 10 . The epitaxial layer 4 is arranged on the first surface of the drift region 2, the doped well 7 is located on the side of the epitaxial layer 4 away from the drift region 2, the doped well 7 has a second doping type, and the doped well 7 also has a first side away from the epitaxial layer 4 and a second side close to the epitaxial layer 4. The gate 6 extends from the first side to the second side into the epitaxial layer 4. The gate oxide layer 5 is arranged around the gate 6 to electrically isolate the gate 6, the epitaxial layer 4 and the doped well 7. The emitter region 8 is arranged on the side of the doped well 7 away from the epitaxial layer 4 and surrounds the gate 6. The dielectric layer 9 is arranged on the first side, the dielectric layer 9 corresponds to the gate 6 one by one and completely covers the gate 6. The emitter metal 10 is located on the first side and contacts the emitter region 8. The collector 11 is located on the side of the collector region 1 away from the drift region 2, and the collector 11 has the same doping type as the collector region 1, and the doping concentration of the collector 11 is greater than the doping concentration of the collector region 1. The collector metal 12 is located on one side of the collector 11 and the short-circuit region 13.

[0030] In some optional embodiments, the material of the epitaxial layer 4 is germanium (Ge). Lattice constant of Si The difference is minimal, which makes it easy to integrate SiGe and Si processes. Due to the mismatch in the lattice constants of Si and SiGe, the Si single crystal layer is subjected to tensile stress by the underlying SiGe layer, which increases the mobility of electrons, thereby increasing the device's operating saturation current and response speed, and improving the device's reliability.

[0031] like Figure 2 As shown, in some optional embodiments, the multiple super junctions include multiple super junction units, each super junction unit includes multiple super junctions, and the projection of each super junction unit on the second surface partially overlaps with the projection of multiple short-circuit regions 13 on the second surface. The multiple super junctions are arranged at intervals along the first direction A, and in the first direction A, according to the overlapping relationship between the short-circuit region 13 and the super junctions, when the short-circuit region 13 overlaps with the projection of the multiple super junctions on the second surface, the multiple super junctions overlapping with the short-circuit region 13 are divided into one super junction unit.

[0032] In the above embodiment, by arranging the projection of the super junction unit on the second surface to partially overlap with the projections of the plurality of short-circuit regions 13 on the second surface, the holes stored in the super junction near the short-circuit region 13 can preferentially enter the short-circuit region 13, such as Figure 3As shown, in the area where the short-circuit area 13 does not exist, the self-bias effect formed by the initial electron flow is significant, so that the bipolar conduction mode is preferentially entered in the area where the short-circuit area 13 does not exist, and as the current increases, the bipolar conduction of the area around the short-circuit area 13 is continuously triggered, thereby reducing the rebound phenomenon.

[0033] In some optional embodiments, the super junction unit includes a first super junction unit 14 and a second super junction unit 15, the first super junction unit 14 and the second super junction unit 15 are alternately arranged along a first direction A, the number of super junctions in the first super junction unit 14 is less than the number of super junctions in the second super junction unit 15, the first super junction unit 14 has a first projection on the second surface, the second super junction unit 15 has a second projection on the second surface, and the first projection and the second projection partially overlap with the projections of the same number of short-circuit areas 13 on the second surface.

[0034] For example, Figure 2 As shown, the first super junction unit 14 includes two adjacent super junctions, and the two adjacent super junctions have overlapping projections with the short-circuit area 13 on the second surface. Along the first direction A, the second super junction unit 15 includes four adjacent super junctions, and the four adjacent super junctions have overlapping projections with the short-circuit area 13 on the second surface. The first super junction unit 14 is adjacent to the second super junction unit 15. On the side of the second super junction unit 15 away from the first super junction unit 14, there are also two adjacent super junctions, and the two adjacent super junctions have overlapping projections with the short-circuit area 13 on the second surface, that is, the first super junction unit 14 and the second super junction unit 15 are alternately arranged along the first direction A.

[0035] In the above embodiment, in order to make the device have a uniform current flow in the first direction A and the third direction C, the number of super junctions in the first super junction unit 14 is set to be smaller than the number of super junctions in the second super junction unit 15, so that the hole storage located in the area near the short-circuit area 13 of each super junction in the device is relatively evenly distributed in the device body.

[0036] In some optional embodiments, the plurality of short-circuit zones 13 include a first short-circuit zone unit 16 and a second short-circuit zone unit 17, the number of short-circuit zones 13 in the first short-circuit zone unit 16 is greater than the number of short-circuit zones 13 in the second short-circuit zone unit 17, the first short-circuit zone unit 16 has a third projection on the first surface, the second short-circuit zone unit 17 has a fourth projection on the first surface, the first projection and the third projection partially overlap, and the second projection and the fourth projection partially overlap.

[0037] Each of the short-circuit area units includes a plurality of short-circuit areas 13, for example, Figure 2As shown, in the first direction A, the first short-circuit zone unit 16 includes a plurality of short-circuit zones 13 overlapping with the projections of two adjacent super junctions on the second surface, and the projection is taken as the third projection. The plurality of short-circuit zones 13 of the second short-circuit unit overlap with the projections of four adjacent super junctions on the second surface, and the projection is taken as the fourth projection.

[0038] In the above embodiment, in order to make the device have a uniform current flow in the first direction A and the third direction C, the number of short-circuit areas 13 in the first short-circuit area unit 16 is greater than the number of short-circuit areas 13 in the second short-circuit area unit 17, so that the hole storage located in the area near the short-circuit area 13 of each super junction in the device is relatively evenly distributed in the device body.

[0039] In some optional embodiments, in the third direction C, the adjacent short-circuit areas 13 in the first short-circuit area unit 16 have the same first spacing, and the adjacent short-circuit areas 13 in the second short-circuit area unit 17 have the same second spacing, and the first spacing is equal to the second spacing. In the above embodiment, the spacing between two adjacent short-circuit areas 13 in the third direction C is used as the first spacing, and the spacing between two adjacent short-circuit areas 13 in the third direction C is set to be equal, so that when the device is turned on, the bipolar current can smoothly transition in the third direction C, and the spacing between two adjacent short-circuit areas 13 in the first direction A is used as the second spacing, and the spacing between two adjacent short-circuit areas 13 in the first direction A is set to be equal, so that when the device is turned on, the bipolar current can smoothly transition in the first direction A.

[0040] In some optional embodiments, each third projection overlaps after extending along the first direction A, and each third projection does not overlap with the fourth projection after extending along the first direction A. In the above embodiment, the third projection is the projection of the first short-circuit zone unit 16 on the second surface, and the fourth projection is the projection of the second short-circuit zone unit 17 on the second surface. When extending along the above first direction A, the above third projection does not overlap with the fourth projection, so that the short-circuit zone 13 in the device can present an orthogonal distribution, which is beneficial to the electron flow in the bipolar conduction region. When the lateral component increases, it triggers the bipolar conduction of the area around the short-circuit zone 13, reduces the problem of uneven current distribution in the device, and improves the rebound phenomenon.

[0041] In some optional implementations, in the third direction C, each first projection has a first area 18 located on both sides of the third projection, and each second projection has a second area 19 located between adjacent fourth projections; in the first direction A, the first area 18 does not overlap with the second area 19 after extension. Figure 4As shown, in the above embodiment, the areas on both sides of the overlapping area of ​​the projections of the first super junction unit 14 and the first short-circuit zone unit 16 are respectively used as first areas 18, and the area between the overlapping area of ​​the projections of the adjacent second super junction unit 15 and the second short-circuit unit is divided into a plurality of second areas 19 having the same area as the first area 18, and in the above first direction A, the first areas 18 and the projections of the second short-circuit units are alternately arranged, and the second areas 19 and the projections of the first short-circuit units are alternately arranged, so that in the above first direction A, the first areas 18 do not overlap with the second areas 19 after being extended.

[0042] Through the arrangement in the above-mentioned embodiment, the above-mentioned first region 18 and second region 19 are used as guide regions in the device. Since there is no short-circuit region 13 in the guide region, the self-bias effect formed by the initial electron flow in the guide region is very significant. Therefore, this region will first enter the bipolar conduction mode and produce a clamping effect. As the current increases, the lateral component of the electron flow in the bipolar conduction region also increases, which will continuously trigger the bipolar conduction of the surrounding guide regions, thereby reducing the rebound phenomenon and rapidly expanding the bipolar conduction range to the entire area of ​​the device.

[0043] The guide area may be in different shapes such as a rectangle or a cross, and its size, number, shape, and area may be designed in different ways. Figure 4 As shown, the device is divided equally into rectangular shapes to ensure that the bipolar current can quickly and smoothly transition from the guide region to the rest of the device when the device is turned on.

[0044] In some optional embodiments, the projected areas of each super junction on the first surface are equal, and the projected areas of each short-circuit region 13 on the first surface are equal, so that the current flow in the device can be evenly distributed, thereby laterally promoting the device to enter full bipolar conduction.

[0045] In some optional embodiments, adjacent super junctions are arranged at equal intervals along the first direction A. In the above embodiments, the super junction structure arranged at equal intervals can reduce the conductivity modulation effect of each part of the device to the same extent, thereby greatly improving the current tailing phenomenon of the device.

[0046] In some optional embodiments, the first direction A is perpendicular to the third direction C. In the above embodiments, since the first direction A is perpendicular to the third direction C, the area around the multiple short-circuit areas 13 in the device is equivalent to a large area of ​​the guide area uniformly distributed around the device, which can be more conducive to reducing rebound and effectively improving the problem of uneven current distribution.

[0047] For example, Figures 2 to 4As shown, the first super junction unit 14 is composed of two super junctions 3, the second super junction unit 15 is composed of four super junctions 3, the first super junction unit 14 and the second super junction unit 15 are alternately arranged along the first direction A, the first short-circuit area unit 16 is composed of four short-circuit areas 13, the second short-circuit area unit 17 is composed of two short-circuit areas 13, the first super junction unit 14 has a first projection on the second surface, the first short-circuit area unit 16 has a third projection on the second surface, and the first projection has areas located on both sides of the third projection along the third direction C, that is, Figure 4 The second super junction unit 15 has a second projection on the second surface, the second short-circuit zone unit 17 has a fourth projection on the second surface, and the second projection has an area between the two third projections along the third direction C, that is, Figure 4 Among the four second regions 19 located in the middle, the first region 18 and the second region 19 have the same area, and in the first direction A, the first region 18 does not overlap with the second region 19 after being extended.

[0048] From the above description, it can be seen that the above embodiments of the present invention achieve the following technical effects:

[0049] By setting a plurality of short-circuit areas at intervals on the second surface of the drift area, the self-bias effect formed by the initial electron flow in the area with uneven short-circuit areas in the above-mentioned device is very significant, so that the area with uneven short-circuit areas will first enter the bipolar conduction mode and produce a clamping effect. Then, as the current increases, the lateral component of the electron flow in the bipolar conduction area also increases, which will continuously trigger the bipolar conduction of the surrounding short-circuit areas, thereby ensuring that the bipolar current quickly and smoothly transitions from the area with uneven short-circuit areas to the short-circuit area when the device is turned on, so that the current distribution in the device is uniform, the rebound phenomenon is greatly weakened, and the stability and reliability of the device operation are improved.

[0050] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An insulated gate bipolar transistor, characterized in that: include: Epitaxial layer; A drift region is formed in the epitaxial layer, the drift region has a first surface and a second surface opposite to each other, and the drift region has a first doping type; A plurality of super junctions are formed in the drift region and spaced apart along a first direction, each of the super junctions extends along a second direction and a third direction, the first direction is parallel to the first surface, the second direction is a direction from the first surface to the second surface, the third direction is parallel to the first surface and different from the first direction, and the super junction has a second doping type; a collector region formed on the second surface in the epitaxial layer, the collector region having the second doping type; a plurality of short-circuit regions formed on the second surface and spaced apart along the third direction, a projection of each of the super junctions on the second surface partially overlapping with a projection of at least one of the short-circuit regions on the second surface, and the short-circuit regions have the first doping type, and a doping concentration of the short-circuit regions is greater than a doping concentration of the drift region; A plurality of the super junctions form a first super junction unit, a plurality of the super junctions form a second super junction unit, the first super junction unit and the second super junction unit are alternately arranged along a first direction, a plurality of the short-circuit areas form a first short-circuit area unit, a plurality of the short-circuit areas form a second short-circuit area unit, the first super junction unit has a first projection on the second surface, the first short-circuit area unit has a third projection on the second surface, the first projection has a first area located on both sides of the third projection along the third direction, the second super junction unit has a second projection on the second surface, the second short-circuit area unit has a fourth projection on the second surface, the second projection has a second area located between adjacent fourth projections along the third direction, and in the first direction, the first area and the second projection are alternately arranged, and the second area and the projection of the first short-circuit unit are alternately arranged.

2. The insulated gate bipolar transistor according to claim 1, wherein: The plurality of super junctions include a plurality of super junction units, each of the super junction units includes a plurality of the super junctions, and a projection of each of the super junction units on the second surface partially overlaps with a projection of the plurality of short-circuit regions on the second surface.

3. The insulated gate bipolar transistor according to claim 2, characterized in that: The super junction unit includes a first super junction unit and a second super junction unit, the number of the super junctions in the first super junction unit is less than the number of the super junctions in the second super junction unit, and the first projection and the second projection partially overlap with projections of the same number of short-circuit regions on the second surface.

4. The insulated gate bipolar transistor according to claim 3, characterized in that: The multiple short-circuit areas include a first short-circuit area unit and a second short-circuit area unit, the number of the short-circuit areas in the first short-circuit area unit is greater than the number of the short-circuit areas in the second short-circuit area unit, the first projection and the third projection partially overlap, and the second projection and the fourth projection partially overlap.

5. The insulated gate bipolar transistor according to claim 4, characterized in that: In the third direction, adjacent short-circuit areas in the first short-circuit area unit have the same first interval, and adjacent short-circuit areas in the second short-circuit area unit have the same second interval, and the first interval is equal to the second interval.

6. The insulated gate bipolar transistor according to claim 4, characterized in that: The third projections overlap after extending along the first direction, and the third projections do not overlap with the fourth projection after extending along the first direction.

7. The insulated gate bipolar transistor according to claim 6, characterized in that: In the third direction, each of the second projections has a plurality of second regions located between adjacent fourth projections, and each of the first regions has an area equal to that of each of the second regions; In the first direction, the first region does not overlap with the second region after being extended.

8. The insulated gate bipolar transistor according to any one of claims 1 to 7, characterized in that: The projected areas of the super junctions on the first surface are equal, and the projected areas of the short-circuit regions on the first surface are equal.

9. The insulated gate bipolar transistor according to any one of claims 1 to 7, characterized in that: Adjacent super junctions are arranged at equal intervals along the first direction.

10. The insulated gate bipolar transistor according to any one of claims 1 to 7, characterized in that: The first direction is perpendicular to the third direction.

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