Schottky diode
By optimizing the doping region distribution and connection method of silicon carbide Schottky diodes and increasing the PN junction area, the problems of forward voltage drop and reverse leakage current were solved, improving the current carrying capacity and surge capability of the device and reducing the process difficulty.
Patent Information
- Application Number
- CN202511163055.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-08-19
- Publication Date
- 2026-02-27
AI Technical Summary
In the process of improving the current carrying capacity and surge current withstand capability of existing silicon carbide Schottky diodes, there are problems such as increased forward voltage drop and increased reverse leakage current, and the manufacturing process is quite difficult.
Design a Schottky diode structure including a substrate, a first doped region, multiple second doped regions, a connection region, an epitaxial layer, a first metal layer, and a second metal layer. By adjusting the distribution and connection method of the doped regions, the PN junction area is increased, the electric field distribution is optimized, the reverse leakage current is reduced, and the current carrying capacity and surge capability of the device are improved.
It effectively reduces the forward conduction voltage drop, enhances the current carrying capacity and surge capability of the device, and at the same time reduces the reverse leakage current and manufacturing difficulty.
Smart Images
Figure CN121586264A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the semiconductor field, and more specifically, to a Schottky diode. Background Technology
[0002] In the field of power electronic devices, silicon carbide Schottky diodes have attracted much attention due to their excellent performance, especially in high-voltage, high-frequency, and high-temperature applications. However, to improve the device's current-carrying capacity and surge current withstand capability, the P-type injection area is often increased. However, excessive P-type injection can increase the device's forward voltage drop, affecting overall efficiency and performance.
[0003] Therefore, there is an urgent need for an innovative design method that can effectively solve the above-mentioned technical problems and improve the overall performance of silicon carbide Schottky diodes.
[0004] The information disclosed above in the background section is only intended to enhance the understanding of the background art of the art described herein. Therefore, the background art may contain certain information that does not constitute prior art known to those skilled in the art in this country. Summary of the Invention
[0005] The main objective of this application is to provide a Schottky diode to address the problem of how to improve the performance of Schottky diodes in the prior art.
[0006] To achieve the above objectives, according to one aspect of this application, a Schottky diode is provided, comprising a substrate, a first doped region, a plurality of second doped regions, a connection region, an epitaxial layer, a first metal layer, and a second metal layer. The doping type of the epitaxial layer is the same as that of the substrate. The first doped region, the connection region, and the plurality of second doped regions are located within the epitaxial layer, and the doping types of the first doped region, the connection region, and the plurality of second doped regions are the same, but different from the doping type of the epitaxial layer. The plurality of second doped regions are respectively located on the outer periphery of the first doped region. One end of the connection region is connected to the first doped region, and the other end is connected to a first target doped region, wherein the first target doped region is a portion of the plurality of second doped regions. The first metal layer is located on the side of the substrate away from the epitaxial layer, and the second metal layer is located on the side of the epitaxial layer away from the substrate.
[0007] Optionally, the area of the first doped region is larger than the area of any one of the second doped regions.
[0008] Optionally, in the direction from the first doped region to the second doped region, the distance between two adjacent second doped regions gradually increases.
[0009] Optionally, the shape of the first doped region is the same as the shape of each of the second doped regions.
[0010] Optionally, multiple second doped regions form multiple annular regions, which sequentially surround the outer periphery of the first doped region, and the geometric center of the annular regions coincides with the geometric center of the first doped region.
[0011] Optionally, among any two adjacent annular regions in the plurality of annular regions, the annular region closer to the first doped region is designated as the first region, and the annular region farther from the first doped region is designated as the second region. Any two adjacent second doped regions in the second region are designated as the second target doped region and the third target doped region, respectively. The second doped region in the first region that is closest to both the second and third target doped regions is designated as the fourth target doped region. The minimum distance between the second and fourth target doped regions is designated as the first distance, the minimum distance between the second and third target doped regions is designated as the second distance, and the minimum distance between the third and fourth target doped regions is designated as the third distance. The first, second, and third distances are all equal.
[0012] Optionally, the annular region can be one of a polygonal ring, a circular ring, or an elliptical ring.
[0013] Optionally, in any annular region, at least two second doped regions are at the same minimum distance from the first doped region.
[0014] Optionally, in multiple annular regions, a portion of the second doped region in the first region is directly connected to the first doped region.
[0015] Optionally, in the first region, the second doped region directly connected to the first doped region is the fifth target doped region, and the fifth target doped region and the first target doped region are arranged alternately.
[0016] This application provides a Schottky diode, comprising a substrate, a first doped region, multiple second doped regions, a connection region, an epitaxial layer, a first metal layer, and a second metal layer. The doping type of the epitaxial layer is the same as that of the substrate. The first doped region, the connection region, and the multiple second doped regions are located within the epitaxial layer. The doping types of the first doped region, the connection region, and the multiple second doped regions are the same, but the doping type of the first doped region differs from that of the epitaxial layer. The multiple second doped regions are located on the outer periphery of the first doped region. One end of the connection region is connected to the first doped region, and the other end is connected to a first target doped region. The first target doped region is a subset of the multiple second doped regions. The first metal layer is located on the side of the substrate away from the epitaxial layer, and the second metal layer is located on the side of the epitaxial layer away from the substrate. In this application, the connection of some second doped regions to the first doped region via the connection region increases the PN junction area, reduces the turn-on condition of the PN junction at that location, makes the PN junction more conductive, increases the device's current carrying capacity, and improves the device's surge capability. Attached Figure Description
[0017] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an undue limitation of this application. In the drawings:
[0018] Figure 1 A top view of a Schottky diode according to an embodiment of this application is shown;
[0019] Figure 2 A kind of Figure 1 Cross-sectional view;
[0020] Figure 3 Another one is shown Figure 1 Cross-sectional view;
[0021] Figure 4 A top view of another Schottky diode according to an embodiment of this application is shown;
[0022] Figure 5 A top view of another Schottky diode according to an embodiment of this application is shown;
[0023] Figure 6 It shows along Figure 5 The cross-sectional view obtained along the C1 direction;
[0024] Figure 7 It shows along Figure 5 The cross-sectional view obtained along the C2 direction;
[0025] Figure 8 A schematic flowchart of a method for fabricating a Schottky diode according to an embodiment of this application is shown.
[0026] The above figures include the following reference numerals:
[0027] 10. Substrate; 11. First doped region; 12. Second doped region; 121. First target doped region; 122. Second target doped region; 123. Third target doped region; 124. Fourth target doped region; 125. Fifth target doped region; 13. Connecting region; 14. Epitaxial layer; 15. First metal layer; 16. Second metal layer. Detailed Implementation
[0028] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of this application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.
[0029] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.
[0030] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate for the embodiments of the invention described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.
[0031] Compared to traditional diodes, Schottky diodes exhibit lower forward voltage drop and, as unipolar devices, higher switching frequencies, shorter reverse recovery times, and lower turn-on losses. Silicon carbide, as a wide bandgap material (3C-SiC: 2.3 eV, 6H-SiC: 2.9 eV, 4H-SiC: 3.2 eV), has a critical breakdown electric field 8 to 10 times higher than silicon. Therefore, compared to silicon-based devices, silicon carbide devices can withstand higher voltages. High-voltage silicon carbide devices can be achieved through highly doped thin drift layers, thereby reducing the on-resistance by several orders of magnitude. A simple Schottky diode, under high reverse bias, will experience increased reverse leakage current due to the lowered Schottky barrier. To reduce the electric field in the Schottky contact region and thus improve the reverse leakage current of the diode, the device can be heavily P-doped to form a structure that utilizes the electric field shielding effect of the high-barrier junction depletion region. The Schottky barrier contact is formed on the surface of the n-type drift layer between two heavily P-type dopants, such as junction barrier Schottky (JBS) diodes or merged PiN Schottky (MPS) diodes. If the spacing between the P-type dopants is too large, it cannot completely form an electric field shield, resulting in increased leakage current; if the spacing is too small, it will increase the on-resistance of the device. The JBS structure consists of P-type implants of the same size and equal spacing and Schottky contacts. Compared with JBS, MPS adds larger P-type implants to the P-type implants of JBS and forms an ohmic contact with the metal on the surface. This ensures that when the transient current is too high, the PiN PN junction in the MPS structure turns on, and the current is shared and flows into the circuit through the ohmic contact metal on the surface, thereby increasing the current carrying capacity of the device. Therefore, MPS can withstand higher surge currents than JBS. When introducing large-size P-implants, MPS may result in insufficient spacing between the implants and surrounding small-size P-implants. This can exceed the limits of photolithography during the manufacturing process or cause insufficient photoresist residue after exposure, posing a significant risk to subsequent processes.
[0032] However, Schottky diodes still have the following problems:
[0033] 1. The spacing between large-size P-implant and small-size P-implant is less than the process limits of the lithography machine and photoresist. After exposure and development, the photoresist will collapse during subsequent processing due to its small size, thus contaminating the wafer.
[0034] 2. The small gap between the large-size P-implant and the small-size P-implant results in a large differential resistance at that point.
[0035] It should be understood that when an element (such as a layer, film, region, or substrate) is described as being "on" another element, the element may be directly on the other element, or there may be an intermediate element present. Furthermore, in the specification and claims, when an element is described as being "connected" to another element, the element may be "directly connected" to the other element, or "connected" to the other element via a third element.
[0036] As described in the background section, the performance of Schottky diodes in the prior art is not ideal. To solve the above problems, embodiments of this application provide a Schottky diode.
[0037] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.
[0038] Figures 1 to 7 This is a schematic diagram of the structure of a Schottky diode according to an embodiment of this application. Figures 1 to 7 As shown, the structure includes: a substrate 10, a first doped region 11, a plurality of second doped regions 12, a connection region 13, an epitaxial layer 14, a first metal layer 15, and a second metal layer 16. The doping type of the epitaxial layer 14 is the same as that of the substrate 10. The first doped region 11, the connection region 13, and the plurality of second doped regions 12 are located within the epitaxial layer 14. The doping types of the first doped region 11, the connection region 13, and the plurality of second doped regions 12 are the same. The doping type of the first doped region 11 is... The doping type is different from that of the epitaxial layer 14. The plurality of the second doped regions 12 are located on the outer periphery of the first doped region 11. One end of the connection region 13 is connected to the first doped region 11, and the other end of the connection region 13 is connected to the first target doped region 121. The first target doped region 121 is the second doped region 12 that is closest to the first doped region 11. The first metal layer 15 is located on the side of the substrate 10 away from the epitaxial layer 14, and the second metal layer 16 is located on the side of the epitaxial layer 14 away from the substrate 10.
[0039] Specifically, Figure 1 A top view of a Schottky diode is shown. Figure 2 For along Figure 1 The cross-sectional view obtained in the C1 direction, Figure 3 For along Figure 1 The cross-sectional view obtained along the C2 direction. (See figure) Figure 1As shown in Figure 3, the substrate 10 can be made of silicon, silicon carbide, gallium nitride, diamond, gallium arsenide, or sapphire. The substrate 10 and the epitaxial layer 14 have the same doping type, but the doping concentration of the epitaxial layer 14 is lower than that of the substrate 10. The first doped region 11, the second doped region 12, and the connection region 13 have the same doping type, while the epitaxial layer 14 and the first doped region 11 have different doping types. Taking the substrate 10 as having an N-type doping type as an example, the epitaxial layer 14 also has an N-type doping type, the first doped region 11, the second doped region 12, and the connection region 13 all have a P-type doping type, and the doping concentrations of the first doped region 11, the second doped region 12, and the connection region 13 are all the same. The first doped region 11, the second doped region 12, and the connection region 13 can be formed by implantation, and the implantation dose and energy of the first doped region 11, the second doped region 12, and the connection region 13 can be the same. The first doped region 11 can be located at the center point of the top view or at a non-center location. The second doped region 12 can be regularly surrounding the first doped region 11 or evenly distributed around the first doped region 11 according to a certain pattern.
[0040] like Figure 1 As shown, the first target doped region 121 is the second doped region 12 that is closest to the first doped region 11 among the plurality of second doped regions 12. In practical applications, the first metal layer 15 can be an ohmic metal, such as platinum, palladium, and nickel, which have high work functions. The surface of the first metal layer 15 that contacts the substrate 10 forms an ohmic contact. The second metal layer 16 can be a Schottky metal, such as aluminum, titanium, molybdenum, and tungsten, which form low-impedance contacts with semiconductor materials. The portion of the second metal layer 16 that contacts the epitaxial layer 14 forms a Schottky contact, and the portion of the second metal layer 16 that contacts the first doped region 11 forms an ohmic contact.
[0041] This embodiment provides a Schottky diode, including a substrate, a first doped region, multiple second doped regions, a connection region, an epitaxial layer, a first metal layer, and a second metal layer. The doping type of the epitaxial layer is the same as that of the substrate. The first doped region, the connection region, and the multiple second doped regions are located within the epitaxial layer. The doping types of the first doped region, the connection region, and the multiple second doped regions are the same, but the doping type of the first doped region is different from that of the epitaxial layer. The multiple second doped regions are located on the outer periphery of the first doped region. One end of the connection region is connected to the first doped region, and the other end of the connection region is connected to a first target doped region. The first target doped region is a portion of the multiple second doped regions. The first metal layer is located on the side of the substrate away from the epitaxial layer, and the second metal layer is located on the side of the epitaxial layer away from the substrate. In this application, the connection of a portion of the second doped regions to the first doped region via the connection region increases the PN junction area, reduces the turn-on condition of the PN junction at that location, makes the PN junction more easily conductive, increases the device's current carrying capacity, and improves the device's surge capability.
[0042] In the specific implementation process, such as Figures 1 to 3 As shown, the area of the first doped region 11 is larger than the area of any one of the second doped regions 12. While ensuring a sufficiently large Schottky area ratio, the large implantation area ratio of the first doped region 11 can further improve the current carrying capacity and surge capability of the Schottky diode while maintaining a small forward voltage drop.
[0043] In the above implementation process, the shape of the first doped region may be the same as or different from the shape of the second doped region. When both the first and second doped regions are circular, the radius of the first doped region is larger than the radius of the second doped region. When both the first and second doped regions are polygonal, the maximum side length of the first doped region is greater than the maximum side length of the second doped region. Furthermore, the areas of the multiple second doped regions may be the same or different.
[0044] like Figure 2 and Figure 3 As shown, in the direction perpendicular to the thickness direction of the substrate 10, the width of the first doped region 11 is greater than the width of the second doped region 12, and also greater than the width of the connection region 13.
[0045] In practical applications, the area of the first doped region is much larger than that of the second doped region. This is because the current in the PN junction is mainly formed by the diffusion of majority carriers, and its expression follows the Shockley diode equation: I = I S (e qv / KT -1), where I S I is the reverse saturation current, and V is the applied forward voltage; with other parameters remaining unchanged, I SThe forward current is positively correlated with the cross-sectional area of the PN junction. Therefore, increasing the junction area will linearly increase the forward current, thereby enhancing the current carrying capacity and surge capability of the device, and making the PN junction easier to conduct.
[0046] To further improve the performance of the Schottky diode, the distance between two adjacent second doped regions gradually increases in the direction from the first doped region to the second doped region. By adjusting the distance between the second doped regions, the electric field distribution of the device can be further optimized, solving the problem of electric field concentration caused by excessively small spacing, thereby further reducing the reverse leakage current. Furthermore, the technical solution in this embodiment can further reduce the reverse leakage current and improve the reverse breakdown voltage of the device.
[0047] In principle, the above implementation scheme can adjust the width of the depletion layer by controlling the distance between the second doped regions, ensuring that the depletion layer can completely cover the Schottky junction under reverse bias, thus avoiding local increases in electric field intensity.
[0048] The above scheme can also be implemented in other ways, for example, by making the shape of the first doped region the same as the shape of each of the second doped regions. This arrangement can further reduce the manufacturing difficulty of Schottky diodes.
[0049] For example, the shapes of the first and second doped regions mentioned above are both circular, elliptical, and quadrilateral. This application does not limit the shape of the connection regions mentioned above; the connection regions can be circular, elliptical, or quadrilateral. Furthermore, the width of the connection regions is less than the minimum required distance for the photolithography process, while all other dimensions meet the process requirements. The width of the connection regions refers to the width of the connection regions along the C2 direction.
[0050] In some embodiments, the above solution can be implemented through the following steps: multiple second doped regions form multiple annular regions, which sequentially surround the outer periphery of the first doped region, with the geometric center of each annular region coinciding with the geometric center of the first doped region. This arrangement can improve the uniformity of the second doped region arrangement, thereby further enhancing the surge capability of the Schottky diode.
[0051] In the above implementation, the distances between the multiple second doped regions and the first doped region within the same annular region are approximately the same. These multiple annular regions form a ring-like shape, arranged sequentially along the direction from the first doped region to the second doped region. Figure 1 This shows a top view of a single cell structure in a Schottky diode; in fact, as shown... Figure 4 As shown, a Schottky diode includes multiple cell structures, and the structure in each cell is similar to... Figure 1 The same as in. For example Figure 4As shown, the area sizes of the multiple first doped regions 11 can be the same or different, and the area sizes of the multiple second doped regions 12 can be the same or different.
[0052] In this invention, such as Figure 1 As shown, in any two adjacent annular regions among the plurality of annular regions, the annular region closer to the first doping region 11 is the first region, and the annular region farther away from the first doping region 11 is the second region. Any two adjacent second doping regions 12 in the second region are the second target doping region 122 and the third target doping region 123, respectively. The second doping region 12 in the first region that is closest to the second target doping region 122 and the third target doping region 123 is the fourth target doping region 124. The minimum distance between the second target doping region 122 and the fourth target doping region 124 is the first distance S1, the minimum distance between the second target doping region 122 and the third target doping region 123 is the second distance S2, and the minimum distance between the third target doping region 123 and the fourth target doping region 124 is the third distance S3. The first distance S1, the second distance S2, and the third distance S3 are equal. In the above structure, S1 = S2 = S3, which can completely shield the Schottky junction between the two second doped regions when reverse voltage is applied, thereby further reducing the leakage current of the Schottky diode.
[0053] Specifically, S1 = S2 = S3, meaning that the center points of the second, third, and fourth target doped regions can form an equilateral triangle. Under otherwise unchanged conditions, the depletion layers of the second, third, and fourth target doped regions can exactly cover the Schottky junction at the center, which represents the upper limit of the spacing between any two of the third, second, and fourth target doped regions. The width of the PN junction depletion region can be calculated using its basic formula: W = [2ε(V bi +V R ) / qN] 1 / 2 , where V bi For the built-in potential, V R ε is the directional voltage, q is the dielectric constant of the semiconductor material, N is the electron charge, and N is the injection concentration.
[0054] In some embodiments, the aforementioned annular region is one of a polygonal ring, a circular ring, and an elliptical ring. This configuration can improve the uniformity of the second doped region arrangement, thereby further enhancing the surge capability of the Schottky diode.
[0055] Specifically, such as Figure 1 As shown, the annular region is a hexagonal ring, such as... Figure 5 As shown, the annular region is a quadrilateral ring. Figure 1 and Figure 5 As shown, the edges of the multiple annular regions are parallel. Figure 5 As shown, the first target doped region 121 is the second doped region 12 that is furthest from the first doped region 11 among the multiple second doped regions 12 in the first region. Figure 5 A top view of another Schottky diode is shown. Figure 6 For along Figure 5 The cross-sectional view obtained in the C1 direction, Figure 7 For along Figure 5 The cross-sectional view obtained in the C2 direction.
[0056] like Figure 1 As shown, in any of the aforementioned annular regions, at least two of the second doped regions 12 have a minimum distance equal to that of the first doped region 11. This arrangement can improve the uniformity of the arrangement of the second doped regions 12, thereby further enhancing the surge capability of the Schottky diode.
[0057] In the above embodiments, if the distances between some of the second doped regions and the first doped region in any annular region are equal, the shape of the annular region is a polygon. If the distances between each second doped region and the first doped region in any annular region are equal, the shape of the annular region is a circle.
[0058] like Figure 5 As shown, a portion of the second doped region 12 in the first region is directly connected to the first doped region 11. This direct connection between the second doped region 12 and the first doped region 11 increases the area of the first doped region 11, further addressing the problem of increased differential resistance caused by excessively narrow spacing at this location.
[0059] Specifically, the direct connection between the second doped region and the first doped region facilitates the formation of a continuous depletion layer, ensuring that the Schottky junction can be completely shielded under reverse bias, thereby reducing reverse leakage current. In other embodiments, the connection method can be changed, such as by using a non-direct connection method, for example, the connection method between the first target doped region and the first doped region, to adapt to different design requirements and solve the problem of electric field distribution optimization caused by specific connection methods.
[0060] like Figure 5 As shown, in the first region described above, the second doped region 12, which is directly connected to the first doped region 11, is the fifth target doped region 125. The fifth target doped region 125 and the first target doped region 121 are arranged alternately. The alternating arrangement of the fifth target doped region 125 and the first target doped region 121 helps to form a more uniform depletion layer, which can ensure that the Schottky junction can be completely shielded under reverse bias, thereby further reducing the reverse leakage current.
[0061] Specifically, the first target doped region is a plurality of second doped regions that are farthest from the first doped region in the first region, and the fifth target doped region is a plurality of second doped regions that are closest to the first doped region in the first region.
[0062] This application also provides a method for fabricating a Schottky diode. Figure 8 This is a schematic flowchart illustrating a method for fabricating a Schottky diode according to an embodiment of this application. Figure 8 As shown, the method includes:
[0063] Step S201, provide a substrate;
[0064] Specifically, the substrate material can be silicon, silicon carbide, gallium nitride, diamond, gallium arsenide, sapphire, etc.
[0065] Step S202: A pre-epitaxial layer is formed on one side of the substrate.
[0066] Specifically, the doping type of the prepared epitaxial layer is the same as that of the substrate, and the doping concentration of the prepared epitaxial layer is less than that of the substrate.
[0067] Step S203: Ion implantation is performed on the above-mentioned pre-epitaxial layer to form a first doped region, a second doped region and a connection region, and the remaining above-mentioned pre-epitaxial layer forms an epitaxial layer.
[0068] The doping types of the first doped region, the second doped region, and the connection region are different from the doping type of the substrate, and the implantation dose and energy of the first doped region, the second doped region, and the connection region can be the same.
[0069] Step S204: A first metal layer is formed on the side of the substrate away from the epitaxial layer;
[0070] In practical applications, the first metal layer can be an ohmic metal, such as platinum, palladium, or nickel, which have high work functions. An ohmic contact is formed between the surface of the first metal layer and the substrate.
[0071] Step S205: A second metal layer is formed on the side of the epitaxial layer away from the substrate.
[0072] Specifically, the second metal layer can be a Schottky metal, such as aluminum, titanium, molybdenum, or tungsten, which forms a low-impedance contact with the semiconductor material. The portion of the second metal layer that contacts the epitaxial layer forms a Schottky contact, and the portion of the second metal layer that contacts the first doped region forms an ohmic contact.
[0073] As can be seen from the above description, the embodiments of the present invention achieve the following technical effects:
[0074] The Schottky diode of this application includes a substrate, a first doped region, multiple second doped regions, a connection region, an epitaxial layer, a first metal layer, and a second metal layer. The doping type of the epitaxial layer is the same as that of the substrate. The first doped region, the connection region, and the multiple second doped regions are located within the epitaxial layer. The doping types of the first doped region, the connection region, and the multiple second doped regions are the same. The doping type of the first doped region is different from that of the epitaxial layer. The multiple second doped regions are located on the outer periphery of the first doped region. One end of the connection region is connected to the first doped region, and the other end of the connection region is connected to a first target doped region. The first target doped region is a portion of the multiple second doped regions. The first metal layer is located on the side of the substrate away from the epitaxial layer, and the second metal layer is located on the side of the epitaxial layer away from the substrate. In this application, the connection of some second doped regions to the first doped region through the connection region can increase the PN junction area, reduce the turn-on condition of the PN junction at that location, making the PN junction easier to conduct, increasing the device's current carrying capacity, and improving the device's surge capability.
[0075] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.
[0076] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.
Claims
1. A Schottky diode, characterized in that, The device includes a substrate, a first doped region, multiple second doped regions, a connection region, an epitaxial layer, a first metal layer, and a second metal layer. The doping type of the epitaxial layer is the same as that of the substrate. The first doped region, the connection region, and the multiple second doped regions are located within the epitaxial layer. The doping types of the first doped region, the connection region, and the multiple second doped regions are the same. The doping type of the first doped region is different from that of the epitaxial layer. The multiple second doped regions are located on the outer periphery of the first doped region. One end of the connection region is connected to the first doped region, and the other end of the connection region is connected to a first target doped region. The first target doped region is a portion of the multiple second doped regions. The first metal layer is located on the side of the substrate away from the epitaxial layer, and the second metal layer is located on the side of the epitaxial layer away from the substrate.
2. The Schottky diode according to claim 1, characterized in that, The area of the first doped region is greater than the area of any one of the second doped regions.
3. The Schottky diode according to claim 1, characterized in that, In the direction from the first doped region to the second doped region, the distance between two adjacent second doped regions gradually increases.
4. The Schottky diode according to claim 1, characterized in that, The shape of the first doped region is the same as the shape of each of the second doped regions.
5. The Schottky diode according to claim 1, characterized in that, Multiple second doped regions form multiple annular regions, which sequentially surround the outer periphery of the first doped region, and the geometric center of the annular regions coincides with the geometric center of the first doped region.
6. The Schottky diode according to claim 5, characterized in that, In any two adjacent annular regions among the plurality of annular regions, the annular region closer to the first doped region is the first region, and the annular region farther from the first doped region is the second region. Any two adjacent second doped regions in the second region are the second target doped region and the third target doped region, respectively. The second doped region in the first region that is closest to the second target doped region and the third target doped region is the fourth target doped region. The minimum distance between the second target doped region and the fourth target doped region is the first distance. The minimum distance between the second target doped region and the third target doped region is the second distance. The minimum distance between the third target doped region and the fourth target doped region is the third distance. The first distance, the second distance, and the third distance are equal.
7. The Schottky diode according to claim 6, characterized in that, The annular region is one of a polygonal ring, a circular ring, or an elliptical ring.
8. The Schottky diode according to claim 6, characterized in that, In any one of the annular regions, at least two of the second doped regions are at the same minimum distance from the first doped region.
9. The Schottky diode according to claim 6, characterized in that, A portion of the second doped region in the first region is directly connected to the first doped region.
10. The Schottky diode according to claim 9, characterized in that, In the first region, the second doped region directly connected to the first doped region is the fifth target doped region, and the fifth target doped region and the first target doped region are arranged alternately.