Semiconductor device

Abstract

The invention discloses a semiconductor device. The semiconductor device includes a plurality of cellular units. The cellular unit comprises: a main body region having a first doping type; and an injection region having a second doping type opposite to the first doping type, the injection region comprising: a first region; the second areas extend from the first area, and contact surfaces of the second areas and the main body area are curved surfaces. The contact surface of the second region and the main body region is a curved surface, which is beneficial to uniform distribution of current and alleviation of electric field peak.

Description

Technical Field

[0001] This application relates to the field of semiconductor technology, and in particular to a semiconductor device. Background Technology

[0002] In the field of power semiconductors, silicon carbide (SiC) has become an ideal choice for fabricating high-voltage, high-temperature, and high-frequency devices due to its wide bandgap, high critical breakdown field strength, and high thermal conductivity. While traditional SiC Schottky barrier diodes (SBDs) exhibit extremely fast reverse recovery characteristics, their reverse leakage current increases sharply with increasing voltage, and their surge current capability is limited. To overcome these shortcomings, the industry has proposed a composite PiN Schottky (MPS) structure. By introducing a P-type doped region, it enhances surge capability under high forward current and suppresses leakage current under reverse bias.

[0003] However, existing composite PiN Schottky diodes exhibit electric field and current concentration, which can lead to overheating or even damage to the device. Summary of the Invention

[0004] In view of the above problems, the purpose of this application is to provide a semiconductor device that can alleviate the phenomenon of electric field and current concentration.

[0005] According to one aspect of the present invention, a semiconductor device is provided, comprising: a plurality of cell units, each cell unit including: a host region having a first doping type; and an implantation region having a second doping type opposite to the first doping type, the implantation region including: a first region; and a plurality of second regions extending from the first region, the contact surface between the second regions and the host region being curved.

[0006] Optionally, the cell unit has 3 to 6 second regions, which are uniformly distributed circumferentially along the first region in the cell unit.

[0007] Optionally, the contact surface between the first region and the main body region is also a curved surface.

[0008] Optionally, the injection region further includes a third region disposed circumferentially along the cell unit, the third region connecting the end of each of the second regions away from the first region.

[0009] Optionally, the contact surface between the third region and the main region is a curved surface.

[0010] Optionally, the area ratio of the injection region to the cell unit is 15% to 40%.

[0011] Optionally, the area ratio of the injection region to the cell unit is 20% to 30%.

[0012] Optionally, a Schottky contact is formed on the surface of the body region, and an ohmic contact is formed on the surface of the injection region.

[0013] Optionally, the apex of the intersection between the injection area and the main body area is a curved surface.

[0014] Optionally, the curvature of the surface is ≥2 micrometers.

[0015] Optionally, the radius of curvature of the surface is 2 to 20 micrometers.

[0016] According to the semiconductor device provided in this application, the contact surface between the second region and the main region is curved, which can disperse the electric field distribution, alleviate the electric field peak, and thus improve the breakdown voltage and reliability of the device. At the same time, the setting of the second region also increases the current diffusion path, effectively reduces the local current density, suppresses the formation of hot spots, and improves the stability of the device under surge conditions. Attached Figure Description

[0017] The above and other objects, features and advantages of this application will become clearer from the following description of embodiments with reference to the accompanying drawings, in which: Figure 1 The diagram shows a schematic structural diagram of a semiconductor device in the XY plane in some embodiments of this application; Figure 2 Show Figure 1 The illustrated embodiment shows a schematic structural diagram of the semiconductor device in multiple XZ planes; Figure 3 This document shows schematic structural diagrams of semiconductor devices in the XY plane in some embodiments of this application; Figure 4 Show Figure 3 The illustrated embodiment shows a schematic structural diagram of the semiconductor device in multiple XZ planes; Figure 5 This document shows schematic structural diagrams of semiconductor devices in the XY plane in some embodiments of this application; Figure 6 Show Figure 5 The schematic structural diagram of the semiconductor device in the XZ plane of the embodiment shown; Figure 7 This diagram illustrates a schematic structural view of the semiconductor device in the XY plane in some of the present embodiments. Figure 8 This diagram illustrates a schematic structural view of the semiconductor device in the XY plane in some of the present embodiments. Figure 9 This diagram illustrates a schematic structure at the apex of the intersection of the injection region and the main body region in some of the embodiments. Detailed Implementation

[0018] Various embodiments of the present application will now be described in more detail with reference to the accompanying drawings. In the various drawings, the same elements are indicated by the same or similar reference numerals. For clarity, the various parts in the drawings are not drawn to scale.

[0019] Furthermore, certain terms are used in this specification and claims to refer to specific components. Those skilled in the art will understand that manufacturers may use different names to refer to the same component. This specification and claims do not use differences in name to distinguish components.

[0020] Furthermore, it should be noted that in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0021] like Figures 1-9 As shown, the first direction is defined as X, the second direction as Y, and the third direction as Z. In the embodiments of this application, the X, Y, and Z directions being perpendicular to each other are used as an example to illustrate the specific implementation process of this application.

[0022] The semiconductor device disclosed in this application includes multiple cell units, which may have the same structure and function, and a complete device is formed by combining multiple cell units.

[0023] like Figure 1 As shown, in some embodiments, taking the semiconductor device 100 as an example including a plurality of first cell units U1, a schematic structural diagram of the semiconductor device 100 is shown.

[0024] In this embodiment, the third direction Z represents the thickness direction of the semiconductor device 100, and the XY plane is a plane perpendicular to the thickness direction of the semiconductor device 100. Figure 1 The cell structure shown can be the structure of the semiconductor device 100 in the XY plane.

[0025] exist Figure 1In the illustrated embodiment, the first cell unit U1 is described as a regular hexagon in the XY plane. It should be understood that in other embodiments, the first cell unit U1 may be other forms of hexagon, square, or other regular polygon, or it may be a hexagon or other polygon stretched along any direction in the XY plane, or it may be a circle or ellipse. This application does not impose any restrictions.

[0026] refer to Figure 1 In the XY plane, the first cell unit U1 can be arranged periodically according to a regular pattern, thereby making the device exhibit a uniform electric field distribution in the current conduction direction. For example, in... Figure 1 The example shows a complete first cell unit U1 arranged in a honeycomb pattern, as well as a portion of multiple first cell units U1 surrounding the circumferential edge of the complete unit.

[0027] The first cell unit U1 includes a main region 111 and an implantation region 112. The main region 111 has a first doping type, and the implantation region 112 has a second doping type opposite to the first doping type. The first doping type can be either N-type or P-type doping, and the second doping type can be either N-type or P-type doping. The N-type doped region is formed by doping the semiconductor material with pentavalent elements such as nitrogen (N), phosphorus (P), arsenic (As), and antimony (Sb), while the P-type doped region is formed by doping the semiconductor material with trivalent elements such as boron (B), aluminum (Al), gallium (Ga), and indium (In).

[0028] In the following embodiments, N-type doping is used as the first doping type and P-type doping is used as the second doping type for illustration.

[0029] In the first cell unit U1, the injection region 112 includes a first region 1121 and a plurality of second regions 1122.

[0030] exist Figure 1 In the example, the first region 1121 is located in the central region of the first cell unit U1 and is circular.

[0031] However, it should be understood that in some other embodiments, the first region may also have other shapes such as ellipse or polygon. Its position may also be off-center from the center of the first cell unit U1.

[0032] The second region 1122 extends from the first region 1121, for example, it may extend from the first region 1121 to the circumferential edge of the first cell unit U1.

[0033] exist Figure 1In the example, the first region 1121 is located at the center of the first cell unit U1, and the second region 1122 extends from the first region 1121 to the corresponding vertex of the first cell unit U1.

[0034] In some embodiments, within the first cell unit U1, the second region 1122 is uniformly distributed circumferentially along the first region 1121. In the hexagonal structure of the first cell unit U1, this is manifested as an angle of 60 degrees between two adjacent second regions 1122.

[0035] Correspondingly, between two adjacent first cell units U1, the second regions 1122 of the two are in contact with each other at the apex corner of the first cell unit U1, and the main regions 111 are in contact with each other at the side of the first cell unit U1.

[0036] In this connection method, within the first cell unit U1, the first region 1121 intersects with each of the second regions 1122 at region J1. Figure 1 An example of such an intersecting region J1 is marked. Between adjacent first cell units U1, the second region 1122 at the vertex junction intersects with region J2. Figure 1 An example of such an intersecting region J2 is marked. When the device is operating, after the current flows through these intersecting regions J1 and J2, it can diffuse in different directions along the injection region 112, thereby improving the surge capability of the device and effectively alleviating the problem of local overheating caused by current concentration.

[0037] In some embodiments, the contact surfaces between the second region 1122 and the main body region 111 are all curved surfaces. For example... Figure 1 As shown, taking a second region 1122 as an example, its two contact surfaces with the main region 111, namely contact surface F1 and contact surface F2, are both curved surfaces. Other second regions 1122 in the same first cell unit U1, as well as second regions 1122 in other first cell units U1, can also have the same curved surface structure.

[0038] The curved structure helps to smooth the electric field distribution, reduce the local electric field concentration effect, and suppress the electric field peak, thereby improving the breakdown voltage and reliability of the device.

[0039] It should be understood that the specific shape of the curved surface is not limited in this application. For example, in the above embodiment, both the first contact surface F1 and the second contact surface F2 are curved surfaces that bulge towards the adjacent injection area 111, and the first contact surface F1 and the second contact surface F2 are completely identical and symmetrically distributed. In some other embodiments, one of the first contact surface F1 and the second contact surface F2 may be a curved surface that bulges towards the adjacent injection area 111, and the other may be a curved surface that bulges away from the adjacent injection area 111; or the first contact surface F1 and the second contact surface F2 may also be wavy or other forms of curved surface.

[0040] In the above Figure 1 In the illustrated embodiment, any second region 1122 has the same surface structure. However, in other embodiments, the second regions 1122 within different first cell units U1 may have different surface structures. For example, each second region 1122 in one first cell unit has a surface convex toward the adjacent injection region 111, while the second regions 1122 in another first cell unit U1 have a surface convex away from the adjacent injection region 111.

[0041] In some embodiments, the radius of curvature of the curved structure is set to be greater than or equal to 2 micrometers (μm), thereby improving the mitigation effect on electric field peaks. When the curvature varies continuously within this range, the phenomenon of electric field concentration can be reduced by 20% to 40%.

[0042] In some other embodiments, the radius of curvature of the curved structure is 2~20μm. By limiting the range of the radius of curvature, the angle between adjacent curved surfaces, i.e., the apex angle of the injection region 111, can be adjusted, thereby suppressing electric field concentration caused by an excessively small angle. Figure 1 In the example, the angle G between two adjacent surfaces is marked.

[0043] By adjusting the radius of curvature of the contact surface, the area ratio of the injection region 112 and the main body region 111 in the first cell unit U1 can also be adjusted.

[0044] For example, in some embodiments, by adjusting the radius of curvature, the injection region 112 can occupy 15% to 40% of the area in the first cell unit U1, and correspondingly, the main body region 111 can occupy 60% to 85% of the area in the first cell unit U1. By adjusting the radius of curvature and the area proportion of each region, the forward conduction voltage drop and reverse leakage characteristics of the device can be balanced.

[0045] In some other embodiments, by adjusting the radius of curvature, the injection region 112 can occupy 20% to 30% of the area in the first cell unit U1, and correspondingly, the main body region 111 can occupy 70% to 80% of the area in the first cell unit U1. By precisely controlling the range of area proportions, the adaptability of the device to operating conditions can be improved, thereby enhancing the versatility of the device.

[0046] In some other embodiments, the accuracy of adjusting the area ratio of each region can be improved by adjusting the radius of curvature and the width h of the main body region 111. Figure 1 The width h of the main body region 111 refers to the distance from the center of the main body region 111 to the circumferential edge.

[0047] It should be pointed out that, in cases such as Figure 1 In embodiments where the first region 1121 is circular, or in other embodiments where the first region 1121 is elliptical, the contact surface between the first region 1121 and the main body region 111 can also be a curved surface, thus suppressing electric field concentration around the first region 1121. It is easy to understand that even when the first region 1121 is polygonal, the sides of the polygon can be set to arbitrary curved surfaces, making the contact surface between the first region 1121 and the main body region 111 also curved, thereby suppressing electric field concentration around the first region 1121.

[0048] Figure 2 Show Figure 1 The schematic structural diagram of the semiconductor device 100 shown is taken in cross-section along the XZ plane. Figure (a) is a schematic diagram of the semiconductor device 100. Figure 1 The XZ plane containing line A-A' is the cross section, and Figure (b) is based on... Figure 1 The XZ plane containing line B-B' is a cross-section.

[0049] refer to Figure 2 In Figures (a) and (b), in semiconductor device 100, the first cell unit U1 includes a semiconductor layer 110 and a metal layer 120.

[0050] The semiconductor layer 110 is, for example, a semiconductor material such as silicon, silicon carbide, gallium nitride, potassium oxide, or diamond, or other group IV semiconductor materials, binary, ternary, or quaternary group III-V semiconductor materials. In some embodiments, hexagonal polymorphic silicon carbide, such as 2H-SiC, 4H-SiC, or 6H-SiC materials, can be selected to improve the high voltage and high temperature resistance of the device.

[0051] The semiconductor layer 110 has a first surface 110a and a second surface 110b opposite to each other. Figure 1The structural diagram shown can be obtained by cutting the semiconductor device 100 with the first surface 110a in the XY plane.

[0052] The semiconductor layer 110 includes a stacked host region 111 and an implantation region 112. Figure 1 In the example, the first surface 110a is also the upper surface of the main body region 111, and the second surface 110b is also the lower surface of the main body region 111.

[0053] In some embodiments, such as Figure 1 As shown, the main body region 111 includes a substrate 1111 and a drift layer 1112 stacked together. Correspondingly, the first surface 110a is also the upper surface of the drift layer 1112, and the second surface 110b is also the lower surface of the substrate 1111.

[0054] In some embodiments, the doping concentration of the substrate 1111 is greater than the doping concentration of the drift layer 1112.

[0055] The injection region 112 extends from the first surface 110a into the main body region 111, in Figure 1 This is manifested in the injection region 112 extending from the upper surface of the drift layer 1112 into the drift layer 1112.

[0056] Corresponding to Figure 1 Line A-A' in Figure 2 In Figure (a), the injection region 112 includes a first region 1121 and two second regions 1122 connected to the first region 1121 in the first direction X. It should be understood that in each second region 1122 in Figure (a), the end furthest from the first region 1121 can be an intersecting region of the second regions 1122 in multiple first cell units U1, i.e. Figure 1 Region J2 in the text. Corresponding to... Figure 1 The B-B' line in Figure 2 In Figure (b), the injection region 112 includes a first region 1121.

[0057] The metal layer 120 includes a first metal layer 121 and a second metal layer 122. The first metal layer 121, the semiconductor layer 110, and the second metal layer 122 are stacked sequentially. The first metal layer 121 and the semiconductor layer 110 are in contact with the first surface 110a, and the second metal layer 122 and the semiconductor layer 110 are in contact with the second surface 110b.

[0058] On the first surface 110a, within the first cell unit U1, the first metal layer 121 and the main region 111, i.e., the drift layer 1112, contact to form a Schottky contact 12, and the first metal layer 121 and the implantation region 112 contact to form a first ohmic contact 13a. On the second surface 110b, the second metal layer 122 and the main region 111, i.e., the substrate 1111, contact to form a second ohmic contact 13b.

[0059] In some embodiments, the first metal layer 121 may be made of a material or composite material suitable for forming the Schottky contact 12 and the first ohmic contact 13a, such as nickel (Ni), titanium (Ti), molybdenum (Mo), platinum (Pt) or other related materials suitable for forming the Schottky contact 12; and nickel-based or titanium-based metal materials suitable for forming the ohmic contact. The second metal layer 122 may be, for example, a nickel-based or titanium-based metal material suitable for forming the ohmic contact.

[0060] Within the first cell unit U1, the first metal layer 121 can also serve as the anode electrode of the first cell unit U1, and the second metal layer 122 can also serve as the cathode electrode of the first cell unit U1.

[0061] When a semiconductor device is operating, the PN junction 11 can be turned on under the action of a surge current, forming a parallel operating mode of the PN junction 11 and the Schottky junction, thereby providing the device with a higher surge current resistance capability.

[0062] It should be understood that the structure of the first cell unit U1 is not limited thereto. For example, in some embodiments, the first cell unit U1 may also have any related structures such as a passivation layer or a field plate.

[0063] Figure 3 This diagram illustrates a schematic structural view of a semiconductor device 200 in the XY plane in some embodiments of this application. The semiconductor device 200 includes a plurality of second cell units U2. Figure 3 In the example, the second cell unit U2 is also illustrated as a regular hexagon arranged in a honeycomb pattern in the XY plane.

[0064] In the second cell unit U2, the injection region 212 includes a first region 2121 and a second region 2122. The configuration of the main region 211, the injection region 212, the first region 2121 and the second region 2122 can be referred to the above description of the main region 111, the injection region 112, the first region 1121 and the second region 1122.

[0065] like Figure 3In the illustrated embodiment, the injection region 212 further includes a third region 2123 in the second cell unit U2. The third region 2123 extends circumferentially along the second cell unit U2 and connects the ends of each second region 2122 away from the first region 2121. That is, the third region 2123 can be a ring structure with the same shape as the second cell unit U2, located at the circumferential edge of the second cell unit U2, and surrounding the first region 2121, the second regions 2122, and the main body region 211.

[0066] The third regions 2123 of two adjacent second cell units U2 are in contact with each other to form an integral structure, and connect the second regions 2122 of adjacent second cell units U2 to form a structure that is spaced apart from each other.

[0067] The third region 2123 increases the number of current paths, thereby improving the device's surge protection capability and helping to meet the high requirements for transient current.

[0068] In some embodiments, the contact surface between the third region 2123 and the main body region 211 can also be any curved surface structure to suppress electric field concentration.

[0069] For example, the contact surfaces of the third region 2123 and the main region 211 may both be curved surfaces convex towards the main region 211, or the contact surfaces of the third region 2123 and the main region 211 may both be curved surfaces convex away from the main region 211, or the contact surface of the third region 2123 with a part of the main region 211 may be a curved surface convex towards that main region 211, and the contact surface with another part of the main region 211 may be a curved surface convex away from that main region 211.

[0070] In some other embodiments, the contact surface between the third region 2123 and the main body region 211 may be partly a curved surface and partly a curved surface. Figure 3 The planar contact surface is shown.

[0071] Figure 4 Show Figure 3 The illustrated embodiment shows a schematic structural diagram of the semiconductor device in multiple XZ planes. Figure (a) is a schematic diagram of the semiconductor device in multiple XZ planes. Figure 1 The XZ plane containing the C-C' line is the cross section, and Figure (b) is based on... Figure 1 The XZ plane containing the D-D' line is a cross-section.

[0072] refer to Figure 4In Figures (a) and (b), in semiconductor device 200, the second cell unit U2 includes a semiconductor layer 210 and a metal layer 220. A description of the semiconductor layer 210, its first surface 210a and second surface 210b, body region 211, substrate 2111, drift layer 2112, implantation region 212, metal layer 220, first metal layer 221, second metal layer 222, Schottky contact 12, first ohmic contact 13a, and second ohmic contact 13b in the XZ plane can be found in [reference needed]. Figure 2 Explanation of the corresponding structure.

[0073] Corresponding to Figure 3 The C-C' line in Figure 4 In Figure (a), the injection region 212 includes a first region 2121, two second regions 2122 adjacent to the first region 2121 in the first direction X, and two third regions 2123 adjacent to the respective second regions 2122 and far from the first region 2121. Figure 4 In Figure (b), the injection region 212 includes a first region 2121 located at the center of the second cell unit U2 and a third region 2123 located at the edge of the second cell unit U2.

[0074] It should be noted that, in Figure 1 In the illustrated embodiment, the main body region 111 is in direct contact between adjacent first cell units U1. This structure facilitates increasing the radius of curvature of the surface and also improves the device's tolerance to process variations. Figure 3 In the illustrated embodiment, adjacent second cell units U2 are separated from the main body region 211 by a third region 2123. This structure helps improve the surge resistance of the device. In actual operating conditions, the cell unit structure can be selected according to the requirements of the scenario.

[0075] Figure 5 This diagram illustrates a schematic structural view of a semiconductor device 300 in the XY plane in some further embodiments of this application. The semiconductor device 300 includes a plurality of third-cell units U3. Figure 5 In the example, the third cell unit U3 is also illustrated as a regular hexagon arranged in a honeycomb pattern in the XY plane.

[0076] The third cell unit U3 includes a host region 311 and an implantation region 312. The host region 311 has a first doping type, and the implantation region 312 has a second doping type opposite to the first doping type.

[0077] In the third cell unit U3, the injection region 312 includes a first region 3121 and three second regions 3122. The first region 3121 is exemplified by being located at the center of the third cell unit U3.

[0078] The second region 3122 extends from the first region 3121. Figure 5 In the example, the second region 3122 extends from the first region 3121 to a portion of the vertex of the third cell unit U3.

[0079] In some embodiments, in order to improve the uniformity of the current, the second region 3122 is uniformly distributed along the circumference of the first region 3121 inside the third cell unit U3, and the included angle between two adjacent second regions 3122 is 120 degrees.

[0080] Accordingly, for two adjacent third cell units U3, the contacting vertices have the same type of doped region. That is, in one third cell unit U3, the vertices connected by the second region 3122 are in contact with the second region 3122 of the adjacent third cell unit U3; the remaining vertices are in contact with the body region 311 of the adjacent third cell unit U3, with the second region 3122 and the body region 311 spaced apart at the vertices. This facilitates the connection between the injection regions 312 of different third cell units U3, thereby expanding the current path.

[0081] Understandable, Figure 5 In the illustrated embodiment, in a third cell unit U3, the end of the second region 3122 that is away from the first region 3121 can also be as shown. Figure 3 As in the illustrated embodiment, the devices are interconnected through a third region to increase the number of current paths, thereby improving the surge protection capability of the devices and making it easier to meet the high requirements for transient current.

[0082] In this structure, the third regions of two adjacent third cell units U3 are in contact with each other to form an integral structure, and connect the second region 3122 of the adjacent third cell units U3 to form a structure that is spaced apart from each other.

[0083] Figure 6 Show Figure 5 The illustrated embodiment shows a schematic structural diagram of the semiconductor device in the XZ plane where the E-E' line is located.

[0084] refer to Figure 6 As shown, in the semiconductor device 300, the third cell unit U3 includes a semiconductor layer 310 and a metal layer 320. A description of the semiconductor layer 310, its first surface 310a and second surface 310b, the body region 311, the substrate 3111, the drift layer 3112, the implantation region 312, the metal layer 320, the first metal layer 321, the second metal layer 322, the Schottky contact 12, the first ohmic contact 13a, and the second ohmic contact 13b in the XZ plane can be found in [reference needed]. Figure 2 Explanation of the corresponding structures in the example shown.

[0085] Corresponding to Figure 5 The E-E' line in Figure 6 In the injection region 312, there are a first region 3121 and a second region 3122 adjacent to the first region 3121 in the first direction X. The other end of the first region 3121 is a drift layer 3112.

[0086] It should be noted that, in Figure 1 and Figure 3 In the illustrated embodiment, the hexagonal first cell unit U1 and second cell unit U2 each have six second regions 1122 and 2122. The second region 1122 corresponds one-to-one with the vertex corner of the first cell unit U1, and the second region 2122 corresponds one-to-one with the vertex corner of the second cell unit U2. Figure 5 In the embodiment shown, the hexagonal third cell unit U3 has three second regions 3122, which correspond to a portion of the vertex corners of the third cell unit U3.

[0087] In other words, this application does not limit the number and positional relationship of the second region in the cell unit. The number and positional relationship of the second region in the cell unit can be specifically set according to the electrical characteristics required by the device and the cell shape. For example, in a non-regular hexagonal polygonal cell structure, the number of the second region can be configured to be the same as the number of vertices of the polygon, or it can be configured to be less than the number of vertices of the polygon.

[0088] In some embodiments, 3 to 6 second regions may be provided in the cell unit to achieve better balance of the device's forward voltage drop (V). f Features and surge resistance.

[0089] In some embodiments, it can also be based on the forward voltage drop (V) of the device under operating conditions. f The number of second zones can be increased or decreased depending on the requirements for characteristics and surge resistance.

[0090] In the aforementioned semiconductor devices 100, 200, and 300, the unit cells are all exemplified as regular hexagons. However, this application does not impose any restrictions on the shape of the unit cells in the XY plane.

[0091] For example, Figure 7 This diagram illustrates a schematic structural view of a semiconductor device 400 in the XY plane in some further embodiments of this application. The semiconductor device 400 includes a plurality of fourth cell units U4. Figure 7 In the example, the fourth cell unit U4 is illustrated as a regular triangle in the XY plane.

[0092] The fourth cell unit U4 includes a host region 411 and an implantation region 412. The host region 411 has a first doping type, and the implantation region 412 has a second doping type opposite to the first doping type.

[0093] In the fourth cell unit U4, the injection region 412 includes a first region 4121 and three second regions 4122. The first region 4121 is exemplified by being located at the center of the fourth cell unit U4.

[0094] The second region 4122 extends from the first region 4121. Figure 7 In the example, the second region 4122 extends from the first region 4121 to each vertex of the fourth cell unit U4.

[0095] In some embodiments, in order to improve the uniformity of the current, the second region 4122 is uniformly distributed along the circumference of the first region 4121 inside the fourth cell unit U4, and the included angle between two adjacent second regions 4122 is 120 degrees.

[0096] Correspondingly, between two adjacent fourth cell units U4, the second regions 4122 of the two are in contact with each other at the apex of the fourth cell unit U4, and the main regions 411 are in contact with each other at the side of the fourth cell unit U4.

[0097] In this connection method, within the fourth cell unit U4, the first region 4121 intersects with each of the second regions 4122 at region J3. Figure 7 An example of such an intersecting region J3 is marked. Between adjacent fourth cell units U4, the second region 4122 at the vertex junction intersects with region J4. Figure 7 An example of such an intersecting region J4 is marked in the figure. When the device is operating, after the current flows through these intersecting regions J3 and J4, it can diffuse in different directions along the injection region 112, thereby improving the surge capability of the device and effectively mitigating the problem of local overheating caused by current concentration.

[0098] like Figure 7 As shown, in the embodiment where the fourth cell unit U4 is an equilateral triangle, six fourth cell units U4 can be joined at their vertices to form a large hexagonal cell unit U5. Therefore, this structure also has the technical characteristics and effects of a hexagonal cell unit, such as improving the efficiency of the semiconductor device 400.

[0099] In some other embodiments, the cell unit may also be a square or other regular polygon, or it may be a polygon stretched in any direction on the XY plane, or it may be a polygon with other deformation methods, which will not be described in detail here.

[0100] Understandable, Figure 7 In the illustrated embodiment, in a fourth cell unit U4, the end of the second region 4122 that is away from the first region 4121 can also be as shown. Figure 3 As in the illustrated embodiment, the devices are interconnected through a third region to increase the number of current paths, thereby improving the surge protection capability of the devices and making it easier to meet the high requirements for transient current.

[0101] In this structure, the third regions of two adjacent fourth cell units U4 are in contact with each other to form an integral structure, and connect the second region 4122 of the adjacent fourth cell units U4 to form a structure that is spaced apart from each other.

[0102] In the above embodiments, the second region extends from the first region towards the apex of the cell as an example. However, it should be understood that in some embodiments, the second region may also extend from the first region towards the side of the cell. For example, Figure 8 This diagram illustrates a schematic structural view of a semiconductor device 500 in the XY plane in some embodiments of this application. The semiconductor device 500 includes a plurality of sixth cell units U6.

[0103] exist Figure 8 In the example, the sixth cell unit U6 is illustrated as a regular hexagon arranged in a honeycomb pattern in the XY plane.

[0104] The sixth cell unit U6 includes a host region 511 and an implantation region 512. The host region 511 has a first doping type, and the implantation region 512 has a second doping type opposite to the first doping type.

[0105] In the sixth cell unit U6, the injection region 512 includes a first region 5121 and a plurality of second regions 5122. The first region 5121 is exemplified by being located at the center of the sixth cell unit U.

[0106] The second region 5122 extends from the first region 5121. Figure 8 In the example, the second region 5122 extends from the first region 5121 to the side of the sixth cell unit U6.

[0107] In some embodiments, each second region 5122 can be uniformly distributed along the circumference of the first region 5121, and the included angle between any two adjacent second regions 5122 is 60°.

[0108] In some embodiments, within the sixth cell unit U6, the second region 5122 extends along the first region 5121 to the midpoint of the side edge of the sixth cell unit U6. This facilitates mutual contact between the second regions 5122 of different sixth cell units U6, thereby extending the current path and improving the uniformity of the current distribution.

[0109] In some embodiments, the number of second regions can be increased or decreased according to the requirements of the device's forward voltage drop (Vf) characteristics and surge immunity under operating conditions. For example, 3 to 6 second regions can be set to achieve a better balance between the device's forward voltage drop (Vf) characteristics and surge immunity.

[0110] Understandable, Figure 8 In the illustrated embodiment, in a sixth cell unit U6, the end of the second region 5122 away from the first region 5121 can also be as shown... Figure 3 As in the illustrated embodiment, the devices are interconnected through a third region to increase the number of current paths, thereby improving the surge protection capability of the devices and making it easier to meet the high requirements for transient current.

[0111] In this structure, the third regions of two adjacent sixth cell units U6 are in contact with each other to form an integral structure, and connect the second region 5122 of the adjacent sixth cell units U6 to form a structure that is spaced apart from each other.

[0112] In any of the above embodiments, the apex points where the injection area intersects with the main body area can also be set as curved surfaces. Figure 9 A schematic structural diagram of the apex where the injection region intersects with the main body region is shown in some of these embodiments. Figure 9 In the middle, to be Figure 1 As an example, the vertices where the injection area 112 intersects with the main body area 111 in the middle region K are set as curved surfaces. And... Figure 9 In the example, the two intersecting vertices L1 and L2 are marked.

[0113] When the corners where the injection region intersects with the main body region are set as curved surfaces, all the places where the injection region and the main body region 111 come into contact within the entire cell are curved surfaces, and there are no sharp corners. This helps to suppress the accumulation of electric field at these corners, thereby reducing the peak electric field and improving the breakdown voltage and reliability of the device.

[0114] According to the semiconductor device provided in this application, the contact surface between the second region and the main region is curved, which can disperse the electric field distribution, alleviate the electric field peak, and thus improve the breakdown voltage and reliability of the device. At the same time, the curved structure increases the current diffusion path, effectively reduces the local current density, suppresses the formation of hot spots, and improves the stability of the device under surge conditions.

[0115] The embodiments described above, as per the examples of this application, do not exhaustively describe all details, nor do they limit this application to the specific embodiments described above. Clearly, many modifications and variations can be made based on the above description. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of this application, thereby enabling those skilled in the art to effectively utilize this application and its modifications. The scope of protection of this application should be determined by the scope defined in the claims of this application.

Claims

1. A semiconductor device, wherein, include: Multiple cell units, The cellular unit includes: The main region has the first doping type; and The implantation region has a second doping type opposite to the first doping type. The injection region includes: First region; and Multiple second regions extending from the first region, wherein the contact surface between the second region and the main region is curved.

2. The semiconductor device according to claim 1, wherein, The cell unit has 3 to 6 of the second regions. The second region is uniformly distributed circumferentially along the first region within the cell unit.

3. The semiconductor device according to claim 1, wherein, The contact surface between the first region and the main body region is also a curved surface.

4. The semiconductor device according to claim 1, wherein, The injection region further includes: A third region is arranged circumferentially along the cell unit, and the third region connects to the end of each of the second regions that is away from the first region.

5. The semiconductor device according to claim 1, wherein, The contact surface between the third region and the main body region is a curved surface.

6. The semiconductor device according to claim 1, wherein, The area ratio of the injection region to the cell unit is 15% to 40%.

7. The semiconductor device according to claim 6, wherein, The area ratio of the injection region to the cell unit is 20% to 30%.

8. The semiconductor device according to claim 1, wherein, The surface of the main body region forms a Schottky contact, and the surface of the injection region forms an Ohmic contact.

9. The semiconductor device according to claim 1, wherein, The apex of the intersection between the injection area and the main body area is a curved surface.

10. The semiconductor device according to any one of claims 1-9, wherein, The curvature of the surface is ≥2 micrometers.

11. The semiconductor device according to claim 10, wherein, The radius of curvature of the surface is 2 to 20 micrometers.

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