Diode structure

Abstract

The invention provides a diode structure. The diode structure comprises a substrate layer body; the filling grooves are formed in the base layer body and extend in the length direction or the width direction of the base layer body, the number of the filling grooves is multiple, and the multiple filling grooves are formed in the length direction or the width direction of the base layer body at intervals; an epitaxial filling layer body is arranged in each filling groove; the first metal layer body is connected with at least one epitaxial filling layer body in the plurality of filling grooves to form first ohmic contact; and a second metal layer body disposed on the base layer body and forming Schottky contact with the base layer body. According to the invention, the problem of low high voltage resistance of the SIC diode in the prior art is solved.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor technology, and in particular to a diode structure. Background Art

[0002] Power diodes are components of circuit systems and are widely used in high-frequency inverters, digital products, generators, televisions and other products. Power diodes are expanding in two important directions: (1) They are developing towards tens of millions or even tens of thousands of amperes, and can be used in high-temperature arc wind tunnels, resistance welding machines and other occasions; (2) The reverse recovery time is getting shorter and shorter, showing a trend towards ultra-fast, ultra-soft, and ultra-durable development, making them not only used in rectification occasions, but also playing different roles in various switching circuits. In order to meet the requirements of low power consumption, high frequency, high temperature, miniaturization and other applications, their withstand voltage, on-resistance, turn-on voltage drop, reverse recovery characteristics, high temperature characteristics, etc. are getting higher and higher.

[0003] Commonly used diodes include ordinary rectifier diodes, Schottky diodes, and PIN diodes. They have their own characteristics compared to each other: Schottky rectifiers have lower on-state voltage drop, larger leakage current, and almost zero reverse recovery time. PIN fast recovery rectifiers have faster reverse recovery time, but their on-state voltage drop is very high.

[0004] At present, with the development of microelectronic devices towards low power consumption, high voltage resistance and high reliability, the requirements for semiconductor materials are gradually increasing. Microelectronic devices are increasingly used in special environments such as high temperature, high radiation, high frequency and high power. In order to meet the application of microelectronic devices in the fields of high temperature resistance and radiation resistance, new semiconductor materials need to be developed to maximize the performance of microelectronic devices. Traditional silicon devices and gallium arsenide devices limit the improvement of device and system performance. The third-generation semiconductor materials represented by silicon carbide (SiC) and gallium nitride (GaN) have become ideal semiconductor materials for making high temperature resistant, high power and radiation resistant electronic devices due to the advantages of the wide bandgap and high critical breakdown electric field of the materials themselves. The SiC-based devices currently under study include high temperature and power SiC devices, microwave and high frequency SiC devices, SiC optoelectronic devices, radiation resistant devices, etc. The critical breakdown field strength of SiC materials is 10 times that of Si materials, the bandgap and thermal conductivity of SiC are both 3 times that of Si materials, and the concentration of intrinsic carriers is only one-tenth of that of silicon materials. These excellent physical properties make semiconductor power devices made of SiC materials have great advantages in high frequency, high temperature, high power and high radiation environments. SiC can form different crystal structures under different environments. The three commonly used crystal structures are 3C-SiC, 4H-SiC and 6H-SiC. 4H-SiC material has become the mainstream material for manufacturing semiconductor devices due to its higher bandgap width and hole mobility and lower intrinsic carrier concentration.

[0005] At present, the SIC diode device structure has not been optimized based on the material characteristics of SIC, resulting in no obvious performance advantages over Si devices in some parameters. The SIC diode uses the traditional process of Si diodes. Affected by the characteristics of SIC materials, the process is complicated and the device has low high-voltage resistance. Summary of the invention

[0006] The main purpose of the present invention is to provide a diode structure to solve the problem of low high voltage resistance of the SIC diode in the prior art.

[0007] In order to achieve the above-mentioned purpose, according to one aspect of the present invention, a diode structure is provided, including: a base layer body; a filling groove, which is arranged on the base layer body, and the filling groove extends along the length direction or the width direction of the base layer body, and there are multiple filling grooves, and the multiple filling grooves are arranged at intervals along the length or width direction of the base layer body; an epitaxial filling layer body is respectively arranged in each filling groove; a first metal layer body is connected to at least one epitaxial filling layer body in the multiple filling grooves to form a first ohmic contact; a second metal layer body is arranged on the base layer body and forms a Schottky contact with the base layer body.

[0008] Furthermore, the filling groove includes: a first filling groove, the groove opening of which gradually increases along the direction from the bottom surface to the top surface of the base layer; and a second filling groove, which is arranged on the side of the first filling groove and has a depth less than that of the first filling groove.

[0009] Furthermore, the epitaxial filling layer body includes: a first epitaxial layer body, arranged in a first filling groove, and at least a portion of the second metal layer body is bonded to the first epitaxial layer body; a second epitaxial layer body, arranged in a second filling groove, and the first metal layer body is connected to the second epitaxial layer body to form a first ohmic contact.

[0010] Further, the doping concentration of the second epitaxial layer body is greater than the doping concentration of the first epitaxial layer body; and / or the width of the first metal layer body is the same as the width of the second epitaxial layer body.

[0011] Furthermore, the first filling groove includes: a first groove section and a second groove section which are interconnected, the second groove section is connected to one end of the first groove section close to the top surface of the base layer, the width of the second groove section is greater than the width of the first groove section, and the depth of the second groove section is less than the depth of the first groove section; wherein, the depth of the second filling groove is greater than the depth of the second groove section and less than the depth of the first groove section.

[0012] Furthermore, the epitaxial filling layer body includes a first epitaxial layer body, and the first epitaxial layer body includes: a first epitaxial segment, arranged in a first groove segment; a second epitaxial segment, arranged in a second groove segment, the doping concentration of the second epitaxial segment is less than the doping concentration of the first epitaxial segment, and at least a portion of the second metal layer body is connected to the second epitaxial segment.

[0013] Furthermore, there are two first filling slots, the second filling slot is located between the two first filling slots, and the two first filling slots are symmetrically arranged relative to a center line of the second filling slot.

[0014] Furthermore, the first metal layer is arranged to protrude from the top surface of the base layer; the second metal layer is provided with an avoidance groove, and the first metal layer is embedded in the avoidance groove.

[0015] Furthermore, the diode structure further includes: a third metal layer body, which is arranged on a side of the base layer body away from the filling groove, and the third metal layer body is connected to the base layer body to form a second ohmic contact.

[0016] Furthermore, the base layer body includes: an N-type substrate; an N-type epitaxial layer, which is arranged on the N-type substrate, a plurality of filling grooves are respectively arranged on the N-type epitaxial layer, and the second metal layer body is connected to the N-type epitaxial layer to form a Schottky contact.

[0017] According to the technical solution of the present invention, the diode structure includes a base layer, a filling groove, a first metal layer and a second metal layer. The filling groove is arranged on the base layer, and the filling groove extends along the length direction or width direction of the base layer. There are multiple filling grooves, and the multiple filling grooves are arranged at intervals along the length or width direction of the base layer; each filling groove is respectively provided with an epitaxial filling layer; the first metal layer is connected to at least one epitaxial filling layer in the multiple filling grooves to form a first ohmic contact; the second metal layer is arranged on the base layer and forms a Schottky contact with the base layer. The combination of multiple filling grooves spaced along the length or width direction of the base layer and the epitaxial filling layer can significantly optimize the current distribution inside the device, avoid hot spots and electric field mutations caused by current concentration, and improve the voltage resistance and reliability of the device. The first metal layer directly forms a first ohmic contact with the epitaxial filling layer, which reduces the resistance loss in the traditional contact mode, thereby reducing the on-resistance of the device and improving the efficiency. The second metal layer forms a Schottky contact with the base layer, which can enhance the height of the Schottky barrier, optimize the reverse recovery characteristics, reduce the reverse leakage current, and improve the performance of the diode. The combination of the filled trench and the epitaxial fill layer body improves the diode's resistance to sudden surge currents by increasing the device's charge storage area, thereby increasing the device's high voltage resistance and reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The drawings constituting a part of the present application 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 drawings:

[0019] Figure 1 A schematic structural diagram of an embodiment of a diode structure according to the present invention is shown;

[0020] Figure 2 A schematic structural diagram of a filling groove of a diode structure according to the present invention is shown;

[0021] Figure 3 It shows a schematic structural diagram of an epitaxial filling layer body in a diode structure according to the present invention;

[0022] Figure 4 A schematic diagram showing the formation of the first metal layer in the diode structure according to the present invention is shown;

[0023] Figure 5 A schematic diagram showing the formation of the second metal layer in the diode structure according to the present invention is shown.

[0024] The above drawings include the following reference numerals:

[0025] 100, base layer; 200, filling groove; 300, epitaxial filling layer; 400, first metal layer; 500, second metal layer; 210, first filling groove; 220, second filling groove; 310, first epitaxial layer; 320, second epitaxial layer; 211, first groove section; 212, second groove section; 311, first epitaxial section; 312, second epitaxial section; 510, avoidance groove; 600, third metal layer; 110, N-type substrate; 120, N-type epitaxy; 130, top surface; 140, bottom surface. DETAILED DESCRIPTION

[0026] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application 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.

[0027] Please refer to Figures 1 to 5 The present application provides a diode structure, including: a base layer body 100; a filling groove 200, which is arranged on the base layer body 100, and the filling groove 200 extends along the length direction or width direction of the base layer body 100, and there are multiple filling grooves 200, and the multiple filling grooves 200 are arranged at intervals along the length or width direction of the base layer body 100; an epitaxial filling layer body 300 is respectively arranged in each filling groove 200; a first metal layer body 400, which is connected to at least one epitaxial filling layer body 300 in the multiple filling grooves 200 to form a first ohmic contact; a second metal layer body 500, which is arranged on the base layer body 100 and forms a Schottky contact with the base layer body 100.

[0028] According to the diode structure provided by the present application, it includes a base layer 100, a filling groove 200, a first metal layer 400 and a second metal layer 500. The filling groove 200 is arranged on the base layer 100, and the filling groove 200 extends along the length direction or width direction of the base layer 100. There are multiple filling grooves 200, and the multiple filling grooves 200 are arranged at intervals along the length or width direction of the base layer 100; each filling groove 200 is respectively provided with an epitaxial filling layer 300; the first metal layer 400 is connected to at least one epitaxial filling layer 300 in the multiple filling grooves 200 to form a first ohmic contact; the second metal layer 500 is arranged on the base layer 100 and forms a Schottky contact with the base layer 100. The combination of multiple filling grooves 200 spaced apart along the length or width direction of the base layer 100 and the epitaxial filling layer 300 can significantly optimize the current distribution inside the device, avoid hot spots and electric field mutations caused by current concentration, and improve the voltage resistance and reliability of the device. The first metal layer 400 directly forms a first ohmic contact with the epitaxial filling layer 300, which reduces the resistance loss in the traditional contact mode, thereby reducing the on-resistance of the device and improving efficiency. The second metal layer 500 forms a Schottky contact with the base layer 100, which can enhance the height of the Schottky barrier, optimize the reverse recovery characteristics, reduce the reverse leakage current, and improve the performance of the diode. The combination of the filling groove 200 and the epitaxial filling layer 300 increases the charge storage area of ​​the device, improves the diode's resistance to sudden surge current, and improves the device's high voltage resistance and reliability.

[0029] In the present application, the depth direction is the direction from the bottom surface 140 to the top surface 130 , and the width direction is perpendicular to the depth direction.

[0030] Specifically, Figure 2 As shown, the filling groove 200 includes: a first filling groove 210, the notch of the first filling groove 210 gradually increases along the direction from the bottom surface 140 to the top surface 130 of the base layer 100; and a second filling groove 220, which is arranged on the side of the first filling groove 210, and the depth of the second filling groove 220 is less than the depth of the first filling groove 210. The gradually increasing notch design of the first filling groove 210 can effectively optimize the electric field distribution, especially in the reverse bias state of the device, it can avoid the concentration of the electric field at the edge of the device, increase the thickness of the PN junction, thereby reducing the breakdown probability and improving the breakdown voltage of the device.

[0031] Since the second filling groove 220 is less deep than the first filling groove 210, it can form a shallower charge trap region, which helps to reduce the leakage current of the device when it is reverse biased. In high-frequency and high-power applications, low leakage current can significantly reduce energy loss and improve system efficiency.

[0032] like Figure 3As shown, in the present application, the epitaxial filling layer body 300 includes: a first epitaxial layer body 310, which is arranged in the first filling groove 210, and at least a portion of the second metal layer body 500 is bonded to the first epitaxial layer body 310; a second epitaxial layer body 320, which is arranged in the second filling groove 220, and the first metal layer body 400 is connected to the second epitaxial layer body 320 to form a first ohmic contact. The bonding of the second metal layer body 500 and the first epitaxial layer body 310, and the connection of the first metal layer body 400 and the second epitaxial layer body 320, form an efficient first ohmic contact and Schottky contact. Ohmic contact reduces the contact resistance of the device and improves the current transmission efficiency; Schottky contact helps to reduce the forward voltage drop and improve the switching speed.

[0033] By arranging the epitaxial layer body in different filling grooves, the distribution of P-type and N-type doped regions can be precisely controlled, the Schottky barrier can be optimized, the leakage current during reverse bias can be significantly reduced, and the reverse blocking performance of the device can be improved.

[0034] The doping concentration of the second epitaxial layer body 320 is greater than the doping concentration of the first epitaxial layer body 310; and / or, the width of the first metal layer body 400 is the same as the width of the second epitaxial layer body 320. When the width of the first metal layer body 400 is the same as the width of the second epitaxial layer body 320, this ensures that the contact area between the metal and the semiconductor material is maximized, thereby improving the efficiency of the ohmic contact. This means that when the device is turned on, the current can pass more smoothly, reducing the contact resistance, reducing the forward voltage drop, and improving the overall efficiency of the device. The high doping concentration of the second epitaxial layer body 320 helps to optimize the electric field distribution inside the device. Under high electric field strength, the area with high doping concentration can effectively disperse the charge and avoid electric field concentration, which helps to improve the breakdown voltage and withstand voltage of the device. The second epitaxial layer body 320 with a high doping concentration can significantly increase the conductivity of the device, thereby improving its current carrying capacity. Among them, the first epitaxial layer body 310 and the second epitaxial layer body 320 are formed by P-type epitaxy.

[0035] The difference in doping concentration between the second epitaxial layer body 320 and the first epitaxial layer body 310 helps to form a more effective barrier and reduce leakage current, especially under reverse bias conditions. This improves the efficiency and reliability of the device in switching applications. The highly doped second epitaxial layer body 320 can provide additional charge storage space, which helps to disperse the current under surge current conditions and avoid local overheating, thereby enhancing the device's surge resistance and improving its reliability in unstable working environments.

[0036] Further, the first filling groove 210 includes: a first groove section 211 and a second groove section 212 which are interconnected, the second groove section 212 is connected to one end of the first groove section 211 close to the top surface of the substrate layer 100, the width of the second groove section 212 is greater than the width of the first groove section 211, and the depth of the second groove section 212 is less than the depth of the first groove section 211; wherein, the depth of the second filling groove 220 is greater than the depth of the second groove section 212 and less than the depth of the first groove section 211. The structural design of the second groove section 212 allows for charge distribution in a wider range, which helps to reduce charge concentration when the device is working, thereby reducing the local electric field strength. The depth difference between the first groove section 211 and the second groove section 212 makes the distribution of charges in different regions more uniform, optimizes the overall electric field distribution, and improves the charge storage capacity and breakdown voltage of the device. The depth difference between the second filling groove 220 and the first filling groove 210 helps to optimize the contact between the metal and the semiconductor and reduce the contact resistance. The first groove section 211 with a greater depth can ensure good electrical connection, while the second filling groove 220 and the second groove section 212 with a greater width provide additional contact paths, making the current distribution more uniform and reducing the overall contact resistance.

[0037] The increase in the width of the second slot section 212 means that the contact area with the metal layer is increased, which is conducive to the rapid diffusion of heat. The depth design of the second filling slot 220 can provide an additional heat conduction path while ensuring electrical performance, thereby improving the overall heat dissipation efficiency and ensuring that the device maintains a stable operating temperature under high power operation.

[0038] Further, the epitaxial filling layer body 300 includes a first epitaxial layer body 310, and the first epitaxial layer body 310 includes: a first epitaxial segment 311, which is arranged in the first slot segment 211; a second epitaxial segment 312, which is arranged in the second slot segment 212, and the doping concentration of the second epitaxial segment 312 is less than the doping concentration of the first epitaxial segment 311, and at least part of the second metal layer body 500 is connected to the second epitaxial segment 312. The high doping concentration of the first epitaxial segment 311 helps to form a more effective carrier blocking layer, while the low doping concentration of the second epitaxial segment 312 helps to reduce the voltage drop during forward conduction. This concentration gradient design can optimize the electric field distribution inside the device, increase the breakdown voltage, and reduce the forward conduction resistance. The first epitaxial segment 311 with a high doping concentration can carry a larger current density, while the low doping design of the second epitaxial segment 312 helps to reduce local overheating and disperse the current when bearing high current, thereby improving the overall current carrying capacity of the device and enhancing its performance in high-power applications.

[0039] The low doping concentration design of the second epitaxial segment 312 helps to reduce the energy storage during the reverse recovery process, thereby shortening the reverse recovery time and reducing the reverse recovery loss, which is particularly important for high-frequency switching applications and can improve the overall efficiency of the system. The connection between the second metal layer 500 and the second epitaxial segment 312 can form a more reliable ohmic contact, reduce contact resistance, and improve current transmission efficiency. Especially under high temperature or high power conditions, this design can ensure stable electrical performance.

[0040] Compared with traditional processes, this design avoids complex doping control and metal deposition steps, simplifies the manufacturing process, reduces production costs, and also improves production yield and device consistency.

[0041] Specifically, there are two first filling grooves 210, and the second filling groove 220 is located between the two first filling grooves 210, and the two first filling grooves 210 are symmetrically arranged relative to the center line of the second filling groove 220. The symmetrically distributed first filling grooves 210 can help optimize the electric field distribution inside the device, avoid the concentration of the electric field at the edge of the device, thereby reducing the local electric field strength and improving the breakdown voltage of the device. The setting of the second filling groove 220 further promotes the uniform distribution of the electric field, especially when the device is subjected to reverse bias, which helps to maintain the stability of the device performance. The shallow depth of the second filling groove 220 and the symmetrical distribution relative to the center line of the first filling groove 210 help to form an effective charge control region and reduce the leakage current during reverse bias. This design is conducive to improving the performance of the device in high-voltage, low-power applications and extending the service life of the device.

[0042] The combination of the first filling groove 210 and the second filling groove 220 increases the contact area between the metal and the semiconductor material, which helps to improve the thermal conductivity and the heat dissipation performance of the device. Under high current or high frequency working conditions, this design can more effectively conduct heat, prevent the device from overheating, and improve its working stability and reliability.

[0043] The first metal layer 400 is arranged to protrude from the top surface of the base layer 100; the second metal layer 500 is provided with an escape groove 510, and the first metal layer 400 is embedded in the escape groove 510. The first metal layer 400 is embedded in the escape groove 510, forming a more optimized current path, which helps to evenly distribute the current inside the device, reduces the hot spots where the current is concentrated, reduces the thermal resistance of the device under large current, and improves the power handling capacity and thermal stability of the device.

[0044] The combination of the protruding design of the first metal layer 400 and the embedded avoidance groove 510 can ensure the stability and reliability of the metal contact during device packaging and use. The protruding metal layer increases the contact area with the semiconductor material, while the embedded design avoids the displacement or damage of the contact point due to stress during the packaging process, thereby improving the mechanical stability of the metal contact. The embedded structural design fixes the first metal layer 400 through the avoidance groove 510, thereby enhancing the mechanical strength of the device, reducing the risk of cracks at the interface between the metal layer and the semiconductor under thermal cycling or mechanical shock, and extending the service life of the device.

[0045] The diode structure further includes: a third metal layer 600, which is disposed on a side of the base layer 100 away from the filling groove 200, and the third metal layer 600 is connected to the base layer 100 to form a second ohmic contact. The third metal layer 600 forms a second ohmic contact, which can effectively disperse and increase the flow path of the current, thereby significantly improving the current carrying capacity of the device, which is for devices that need to handle high currents.

[0046] The base layer 100 includes: an N-type substrate 110; an N-type epitaxial 120, which is arranged on the N-type substrate 110, a plurality of filling grooves 200 are respectively arranged on the N-type epitaxial 120, and a second metal layer 500 is connected to the N-type epitaxial 120 to form a Schottky contact. The plurality of filling grooves 200 arranged on the N-type epitaxial 120 can effectively disperse the charge and optimize the electric field distribution. In particular, under reverse bias conditions, this design can avoid local concentration of the electric field and reduce charge traps, thereby significantly improving the breakdown voltage and high voltage resistance of the device. The existence of the filling groove 200 and its combination with the N-type epitaxial 120 help to form an effective carrier blocking layer and reduce reverse leakage current. The direct contact between the second metal layer 500 and the N-type epitaxial 120 forms a low-resistance, high-stability Schottky contact. This contact method can significantly reduce the forward voltage drop of the device and improve the switching speed, and is particularly suitable for high-frequency and high-power applications. The filling groove 200 is directly formed on the N-type epitaxial 120 , thereby avoiding the complicated traditional processes such as ion implantation, simplifying the manufacturing process, reducing the production cost, and improving the production yield.

[0047] The existence of the filling groove 200 and its combination with the N-type epitaxial layer 120 help to form an effective carrier blocking layer and reduce reverse leakage current.

[0048] The diode structure of this application adopts a trench + multiple epitaxial scheme based on the traditional SIC JBS structure to improve the device's high-voltage resistance. The combination of epitaxial regions with different doping concentrations greatly reduces the leakage current of the device; the trench epitaxial scheme does not require ion implantation, simplifies the process, and reduces the production cost; the ohmic contact and Schottky contact improve the device's surge capability and reduce the forward voltage drop while ensuring the voltage resistance performance.

[0049] In the specific manufacturing process, an N-type SIC substrate and an N-type epitaxial are used, and a first groove section 211, a second filling groove 220 and a second groove section 212 are formed on the surface by dry etching, the depth of the first groove section 211 is greater than the second filling groove 220, the depth of the second filling groove 220 is greater than the second groove section 212, and the width of the first groove section 211 is less than the second filling groove 220 and less than the second groove section 212; SIC epitaxy is prepared, and a P-type epitaxial filling groove is used to fill the groove, and the doping concentration of the second epitaxial layer body 320 is greater than that of the first epitaxial section 311 and greater than that of the second epitaxial section 312. The high concentration of the second epitaxial layer body 320 can improve the surge resistance of the device, and the concentration of the second epitaxial section 312 is less than that of the first epitaxial section 311, which can improve the Schottky The potential barrier reduces leakage, and the first epitaxial segment 311 can increase the device breakdown voltage when reverse biased; prepare a first metal layer 400 (which can be metal nickel), the first metal layer 400 covers the second epitaxial layer 320, and performs thermal annealing (temperature greater than 900°C) to form an ohmic contact; prepare a second metal layer 500 (which can be metal aluminum or metal TI), the second metal layer 500 is prepared at high temperature (temperature greater than 400°C), and thermal annealing is performed simultaneously during the preparation of the second metal layer 500, and a Schottky contact is formed between the second metal layer 500 and the SIC surface; prepare a third metal layer 600 on the back side (conventional process, a TI / NI / Ag three-layer structure can be used) to form an ohmic contact.

[0050] The diode structure of the present application avoids the traditional Al ion implantation step and simplifies the overall process complexity by adopting the trench + multiple epitaxial technology. The novel SIC device structure, combined with the epitaxial regions with different doping concentrations, optimizes the electric field distribution, reduces the leakage current, and improves the high voltage resistance. The optimized metal contact design, such as the combination of the first metal layer 400 and the second metal layer 500, increases the contact area, is conducive to the rapid diffusion of heat, improves the heat dissipation performance of the device, and improves the working stability and reliability in high power and high temperature environments. It avoids processes such as ion implantation that may introduce defects, reduces the failure rate in the manufacturing process, and improves the production yield of the diode. Through the trench design and epitaxial layers with different doping concentrations, this process optimizes the current distribution, reduces local overheating and electric field concentration, reduces the forward voltage drop, and improves the surge current capability of the device.

[0051] From the above description, it can be seen that the above embodiments of the present invention achieve the following technical effects:

[0052] According to the diode structure provided by the present application, it includes a base layer 100, a filling groove 200, a first metal layer 400 and a second metal layer 500. The filling groove 200 is arranged on the base layer 100, and the filling groove 200 extends along the length direction or width direction of the base layer 100. There are multiple filling grooves 200, and the multiple filling grooves 200 are arranged at intervals along the length or width direction of the base layer 100; each filling groove 200 is respectively provided with an epitaxial filling layer 300; the first metal layer 400 is connected to at least one epitaxial filling layer 300 in the multiple filling grooves 200 to form a first ohmic contact; the second metal layer 500 is arranged on the base layer 100 and forms a Schottky contact with the base layer 100. The combination of multiple filling grooves 200 spaced apart along the length or width direction of the base layer 100 and the epitaxial filling layer 300 can significantly optimize the current distribution inside the device, avoid hot spots and electric field mutations caused by current concentration, and improve the voltage resistance and reliability of the device. The first metal layer 400 directly forms a first ohmic contact with the epitaxial filling layer 300, which reduces the resistance loss in the traditional contact mode, thereby reducing the on-resistance of the device and improving efficiency. The second metal layer 500 forms a Schottky contact with the base layer 100, which can enhance the height of the Schottky barrier, optimize the reverse recovery characteristics, reduce the reverse leakage current, and improve the performance of the diode. The combination of the filling groove 200 and the epitaxial filling layer 300 increases the charge storage area of ​​the device, improves the diode's resistance to sudden surge current, and improves the device's high voltage resistance and reliability.

[0053] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0054] Unless otherwise specifically stated, the relative arrangement, numerical expressions and numerical values ​​of the parts and steps set forth in these embodiments do not limit the scope of the application. Meanwhile, it should be understood that, for ease of description, the sizes of the various parts shown in the accompanying drawings are not drawn according to actual proportional relationships. The technology, methods and equipment known to those of ordinary skill in the relevant art may not be discussed in detail, but in appropriate cases, the technology, methods and equipment should be considered as a part of the specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters represent similar items in the following drawings, and therefore, once a certain item is defined in an accompanying drawing, it does not need to be further discussed in subsequent drawings.

[0055] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0056] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0057] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application 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 numbers used in this way can be interchanged where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein.

[0058] 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. A diode structure, characterized in that: include: A base layer body (100); A filling groove (200) is arranged on the base layer (100), the filling groove (200) extends along the length direction or the width direction of the base layer (100), there are a plurality of the filling grooves (200), and the plurality of the filling grooves (200) are arranged at intervals along the length direction or the width direction of the base layer (100); an epitaxial filling layer (300) is respectively arranged in each of the filling grooves (200); A first metal layer body (400) connected to at least one of the epitaxial filling layer bodies (300) in the plurality of filling grooves (200) to form a first ohmic contact; The second metal layer (500) is disposed on the base layer (100) and forms a Schottky contact with the base layer (100).

2. The diode structure according to claim 1, characterized in that: The filling tank (200) comprises: A first filling groove (210), wherein the groove opening of the first filling groove (210) gradually increases in size along the direction from the bottom surface to the top surface of the base layer (100); The second filling groove (220) is arranged on the side of the first filling groove (210), and the depth of the second filling groove (220) is smaller than the depth of the first filling groove (210).

3. The diode structure according to claim 2, characterized in that: The epitaxial filling layer body (300) comprises: A first epitaxial layer body (310) is disposed in the first filling groove (210), and at least a portion of the second metal layer body (500) is bonded to the first epitaxial layer body (310); The second epitaxial layer body (320) is disposed in the second filling groove (220), and the first metal layer body (400) is connected to the second epitaxial layer body (320) to form the first ohmic contact.

4. The diode structure according to claim 3, characterized in that: The doping concentration of the second epitaxial layer body (320) is greater than the doping concentration of the first epitaxial layer body (310); and / or, The width of the first metal layer (400) is the same as the width of the second epitaxial layer (320).

5. The diode structure according to claim 2, characterized in that: The first filling tank (210) comprises: A first groove section (211) and a second groove section (212) are connected to each other, the second groove section (212) is connected to one end of the first groove section (211) close to the top surface of the base layer (100), the width of the second groove section (212) is greater than the width of the first groove section (211), and the depth of the second groove section (212) is less than the depth of the first groove section (211); Wherein, the depth of the second filling groove (220) is greater than the depth of the second groove section (212), and less than the depth of the first groove section (211).

6. The diode structure according to claim 5, characterized in that: The epitaxial filling layer body (300) comprises a first epitaxial layer body (310), wherein the first epitaxial layer body (310) comprises: A first extension section (311) is arranged in the first slot section (211); A second epitaxial segment (312) is disposed in the second groove segment (212), the doping concentration of the second epitaxial segment (312) is lower than the doping concentration of the first epitaxial segment (311), and at least a portion of the second metal layer (500) is connected to the second epitaxial segment (312).

7. The diode structure according to claim 2, characterized in that: There are two first filling grooves (210), the second filling groove (220) is located between the two first filling grooves (210), and the two first filling grooves (210) are symmetrically arranged relative to the center line of the second filling groove (220).

8. The diode structure according to claim 1, characterized in that: The first metal layer (400) is arranged to protrude from the top surface of the base layer (100); The second metal layer (500) is provided with an escape groove (510), and the first metal layer (400) is embedded in the escape groove (510).

9. The diode structure according to claim 1, characterized in that: The diode structure further comprises: The third metal layer (600) is arranged on a side of the base layer (100) away from the filling groove (200), and the third metal layer (600) is connected to the base layer (100) to form a second ohmic contact.

10. The diode structure according to claim 1, characterized in that: The base layer (100) comprises: N-type substrate (110); The N-type epitaxy (120) is arranged on the N-type substrate (110), the plurality of filling grooves (200) are respectively arranged on the N-type epitaxy (120), and the second metal layer (500) is connected to the N-type epitaxy (120) to form the Schottky contact.

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