Bidirectional electrostatic discharge device and radio frequency port device

Abstract

The utility model discloses a bidirectional electrostatic discharge device and a radio frequency port device, and the bidirectional electrostatic discharge device comprises two unidirectional electrostatic discharge devices. The unidirectional electrostatic discharge device comprises a substrate; the epitaxial layer is arranged on one side of the substrate; the buried layer is arranged on one side, far away from the substrate, of the epitaxial layer; the intrinsic epitaxial layer is arranged on one side, far away from the substrate, of the epitaxial layer; the orthographic projection of the intrinsic epitaxial layer on the substrate covers the orthographic projection of the buried layer on the substrate; the body region, the first active region and the second active region are arranged on one side, far away from the substrate, of the intrinsic epitaxial layer; the first conductive layer is arranged on one side, far away from the substrate, of the intrinsic epitaxial layer, and the first conductive layer is connected with the first active region and the second active region respectively; the two unidirectional electrostatic discharge devices are connected through a first conductive layer; the second conductive layer is arranged on one side, far away from the epitaxial layer, of the substrate; the second conductive layer is used as an input port of the bidirectional electrostatic discharge device. The capacitance value of the bidirectional electrostatic discharge device is effectively reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of electrostatic protection, in particular to a bidirectional electrostatic discharge device and a radio frequency port device. Background Art

[0002] In radio frequency integrated circuits (RFICs), electrostatic discharge (ESD) design has become a critical factor affecting RFIC reliability and RF performance. Generally, to achieve greater ESD robustness, a larger ESD device is required. However, in RF circuits, a larger ESD device corresponds to greater parasitic capacitance. This parasitic capacitance can severely interfere with RF circuits, leading to unstable performance. Utility Model Content

[0003] The utility model provides a bidirectional electrostatic discharge device and a radio frequency port device, which solve the problem of large parasitic capacitance of the current ESD device while ensuring that the ESD device has sufficiently large ESD robustness.

[0004] In a first aspect, the present invention provides a bidirectional electrostatic discharge device, wherein the bidirectional electrostatic discharge device includes two unidirectional electrostatic discharge devices connected in series; the unidirectional electrostatic discharge device includes:

[0005] substrate;

[0006] an epitaxial layer disposed on one side of the substrate along a first direction, wherein the first direction is a thickness direction of the substrate;

[0007] A buried layer disposed on a side of the epitaxial layer away from the substrate along a first direction;

[0008] An intrinsic epitaxial layer is provided on a side of the epitaxial layer away from the substrate along a first direction; an orthographic projection of the intrinsic epitaxial layer on the substrate covers an orthographic projection of the buried layer on the substrate;

[0009] Along a first direction, a body region, a first active region, and a second active region are arranged on a side of the intrinsic epitaxial layer away from the substrate, wherein the first active region is located on a side of the body region away from the substrate; along a second direction, the second active region and the first active region are arranged on the same side; the second direction is a direction parallel to the plane of the substrate;

[0010] A first conductive layer is provided on a side of the intrinsic epitaxial layer away from the substrate along a first direction, the first conductive layer being connected to the first active region and the second active region respectively; and two unidirectional electrostatic discharge devices are connected via the first conductive layer;

[0011] A second conductive layer is provided on a side of the substrate away from the epitaxial layer along the first direction; the second conductive layer serves as an input port of the bidirectional electrostatic discharge device.

[0012] Optionally, the unidirectional electrostatic discharge device further includes: an isolation structure;

[0013] The isolation structure penetrates the intrinsic epitaxial layer and the epitaxial layer and extends to the substrate. Along the second direction, the isolation structure divides the intrinsic epitaxial layer, the epitaxial layer and the substrate into a first region and a second region.

[0014] The body region and the first active region are located in the first area; the second active region and the buried layer are located in the second area.

[0015] Optionally, the unidirectional electrostatic discharge device further includes: a dielectric layer;

[0016] The dielectric layer is located between the intrinsic epitaxial layer and the first conductive layer. The orthographic projection of the dielectric layer on the substrate covers the orthographic projection of the intrinsic epitaxial layer on the substrate, the orthographic projection of the first active area on the substrate, and the orthographic projection of the second active area on the substrate. The first conductive layer penetrates the dielectric layer and is connected to the first active area and the second active area.

[0017] Optionally, the unidirectional electrostatic discharge device further includes: a passivation layer;

[0018] Along the second direction, the passivation layer is located on both sides of the first conductive layer; the passivation layer is used to physically protect the first conductive layer.

[0019] Optionally, the doping concentration of the buried layer is less than the doping concentration of the epitaxial layer; the doping types of the substrate and the second active region include a first doping type, and the doping types of the epitaxial layer, the body region, the first active region and the buried layer include a second doping type.

[0020] Optionally, the thickness of the intrinsic epitaxial layer is 10-20 um, and the resistivity is greater than 100 Ω·cm; the thickness of the substrate is 600-650 um, and the resistivity is 0.001-0.05 Ω·cm; the thickness of the epitaxial layer is 4-10 um, and the resistivity is 1-10 Ω·cm.

[0021] In a second aspect, the present invention provides a radio frequency port device, wherein the radio frequency port device includes the bidirectional electrostatic discharge device provided in the first aspect.

[0022] The technical solution of the present utility model is to set an intrinsic epitaxial layer with high resistivity in the bidirectional electrostatic discharge device. The width of the spatial barrier region formed by the intrinsic epitaxial layer and other film layers is relatively large, so that the barrier capacitance is relatively small, which effectively reduces the parasitic capacitance of the bidirectional electrostatic discharge device. At the same time, the bidirectional electrostatic discharge device is formed by two unidirectional electrostatic discharge devices connected in series. The series connection method can further effectively reduce the overall capacitance of the bidirectional electrostatic discharge device. The technical solution of the present utility model effectively reduces the capacitance value of the bidirectional electrostatic discharge device while ensuring that the bidirectional electrostatic discharge device has sufficiently large ESD robustness, thereby effectively improving the performance and reliability of the radio frequency circuit.

[0023] It should be understood that the content described in this section is not intended to identify the key or important features of the embodiments of the present invention, nor is it intended to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0025] Figure 1 This is a schematic structural diagram of a bidirectional electrostatic discharge device provided by an embodiment of the present utility model;

[0026] Figure 2 yes Figure 1 Equivalent circuit diagram of bidirectional electrostatic discharge device;

[0027] Figure 3 This is a flow chart of a method for preparing a bidirectional electrostatic discharge device provided by an embodiment of the present utility model;

[0028] Figure 4 This is a structural diagram corresponding to a step in a method for preparing a bidirectional electrostatic discharge device provided by an embodiment of the present utility model;

[0029] Figure 5 This is a method for preparing a bidirectional electrostatic discharge device provided by the embodiment of the utility model. Figure 4 A structural diagram corresponding to the steps following the method steps;

[0030] Figure 6 This is a method for preparing a bidirectional electrostatic discharge device provided by the embodiment of the utility model. Figure 5 A structural diagram corresponding to the steps following the method steps;

[0031] Figure 7 This is a method for preparing a bidirectional electrostatic discharge device provided by the embodiment of the utility model. Figure 6 A structural diagram corresponding to the steps following the method steps;

[0032] Figure 8 This is a method for preparing a bidirectional electrostatic discharge device provided by the embodiment of the utility model. Figure 7 A structural diagram corresponding to the steps following the method steps;

[0033] Figure 9 This is a method for preparing a bidirectional electrostatic discharge device provided by the embodiment of the utility model. Figure 8 A structural diagram corresponding to the steps following the method steps;

[0034] Figure 10 This is a flow chart of another method for preparing a bidirectional electrostatic discharge device provided by an embodiment of the present utility model;

[0035] Figure 11 This is a method for preparing a bidirectional electrostatic discharge device provided by the embodiment of the utility model. Figure 8 A structural diagram corresponding to the steps following the method steps;

[0036] Figure 12 This is a flow chart of another method for preparing a bidirectional electrostatic discharge device provided by an embodiment of the present utility model;

[0037] Figure 13 This is a flow chart of another method for preparing a bidirectional electrostatic discharge device provided by an embodiment of the present utility model;

[0038] Figure 14 This is a method for preparing a bidirectional electrostatic discharge device provided by the embodiment of the utility model. Figure 9 The structural diagram corresponding to the steps following the method steps. DETAILED DESCRIPTION

[0039] In order to help those skilled in the art better understand the present invention, the following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.

[0040] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0041] Figure 1This is a schematic diagram of the structure of a bidirectional electrostatic discharge device provided by an embodiment of the present utility model. Figure 1 As shown, the bidirectional ESD device includes two unidirectional ESD devices 20 connected in series. The unidirectional ESD device 20 includes: a substrate 1; an epitaxial layer 2 disposed on one side of the substrate 1 along a first direction Y, where the first direction Y is the thickness direction of the substrate 1; a buried layer 4 disposed on the side of the epitaxial layer 2 away from the substrate 1 along the first direction Y; an intrinsic epitaxial layer 3 disposed on the side of the epitaxial layer 2 away from the substrate 1 along the first direction Y, where the orthographic projection of the intrinsic epitaxial layer 3 on the substrate 1 covers the orthographic projection of the buried layer 4 on the substrate 1; a body region 5, a first active region 6, and a second active region 7 disposed on the side of the intrinsic epitaxial layer 3 away from the substrate 1 along the first direction Y, where the first active region 6 is located on the side of the body region 5 away from the substrate 1; and second active region 7 disposed on the same side as the first active region 6 along a second direction X, where the second direction X is parallel to the plane of the substrate 1. A first conductive layer 8 is provided on the side of the intrinsic epitaxial layer 3 away from the substrate 1 along the first direction Y. The first conductive layer 8 is connected to the first active area 6 and the second active area 7, respectively. The two unidirectional ESD devices 20 are connected through the first conductive layer 8. A second conductive layer 9 is provided on the substrate 1 away from the epitaxial layer 2 along the first direction Y. The second conductive layer 9 serves as the input port of the bidirectional ESD device.

[0042] Specifically, the substrate 1 may be a heavily doped silicon carbide substrate or a gallium nitride substrate of the first doping type, the epitaxial layer 2 may be a lightly doped silicon carbide epitaxial layer or a gallium nitride epitaxial layer of the second doping type, the intrinsic epitaxial layer 3 may be a silicon carbide intrinsic semiconductor or a gallium nitride intrinsic semiconductor, the buried layer 4 may be a lightly doped silicon carbide buried layer or a gallium nitride buried layer of the second doping type, the body region 5 may be a lightly doped silicon carbide body region or a gallium nitride body region of the second doping type, the first active region 6 may be a heavily doped silicon carbide active region or a gallium nitride active region of the second doping type, and the second active region 7 may be a heavily doped silicon carbide active region or a gallium nitride active region of the first doping type. The first conductive layer 8 and the second conductive layer 9 may be metal conductive layers.

[0043] The two unidirectional electrostatic discharge devices 20 in the bidirectional electrostatic discharge device are connected in series through the first conductive layer 8. The input ports of the bidirectional electrostatic discharge device include a first input port IO1 and a second input port IO2. The second conductive layer 9 of one unidirectional electrostatic discharge device 20 serves as the first input port IO1, and the second conductive layer 9 of the other unidirectional electrostatic discharge device 20 serves as the second input port IO2.

[0044] According to the technical solution of the embodiment of the present utility model, an intrinsic epitaxial layer with high resistivity is provided in the bidirectional electrostatic discharge device. The width of the spatial barrier region formed by the intrinsic epitaxial layer and other film layers is relatively large, so that the barrier capacitance is relatively small, thereby effectively reducing the parasitic capacitance of the bidirectional electrostatic discharge device. At the same time, the bidirectional electrostatic discharge device is formed by two unidirectional electrostatic discharge devices connected in series. The series connection method can further effectively reduce the overall capacitance of the bidirectional electrostatic discharge device. The technical solution of the embodiment of the present utility model effectively reduces the capacitance value of the bidirectional electrostatic discharge device while ensuring that the bidirectional electrostatic discharge device has sufficiently large ESD robustness, thereby effectively improving the performance and reliability of the radio frequency circuit.

[0045] Optionally, based on the above embodiment, continue to refer to Figure 1 The unidirectional ESD device 20 further includes an isolation structure 10. The isolation structure 10 penetrates the intrinsic epitaxial layer 3 and the epitaxial layer 2 and extends to the substrate 1. Along the second direction X, the isolation structure 10 divides the intrinsic epitaxial layer 3, the epitaxial layer 2, and the substrate 1 into a first region 21 and a second region 22. The body region 5 and the first active region 6 are located in the first region 21; the second active region 7 and the buried layer 4 are located in the second region 22.

[0046] Specifically, the isolation structure 10 extends through the intrinsic epitaxial layer 3 and the epitaxial layer 2 and extends to the substrate 1. For example, the isolation structure 10 may extend to the middle of the substrate 1. The isolation structure 10 may comprise an insulating material such as silicon oxide. By providing the isolation structure 10, the bidirectional electrostatic discharge device provided in the embodiment of the present invention can prevent mutual interference between current and voltage signals in different regions of the device, thereby ensuring the reliability and stability of the device.

[0047] For example, Figure 2 yes Figure 1 The equivalent circuit diagram of the bidirectional electrostatic discharge device in FIG. Figure 2 As shown, the bidirectional ESD device may include a first unidirectional ESD device 21 and a second unidirectional ESD device 22 . Figure 1 The unidirectional electrostatic discharge device 20 includes a first unidirectional electrostatic discharge device 21 or a second unidirectional electrostatic discharge device 22, Figure 1The unidirectional ESD device 20 in the embodiment can be either a first unidirectional ESD device 21 or a second unidirectional ESD device 22. The first unidirectional ESD device 21 can include a first low-capacitance diode D11, a second low-capacitance diode D21, and a first voltage-stabilizer diode Z11. The second unidirectional ESD device 22 can include a third low-capacitance diode D12, a fourth low-capacitance diode D22, and a second voltage-stabilizer diode Z12. The first low-capacitance diode D11 and the third low-capacitance diode D12 can have the same structure, the second low-capacitance diode D21 and the fourth low-capacitance diode D22 can have the same structure, and the first voltage-stabilizer diode Z11 and the second voltage-stabilizer diode Z12 can have the same structure.

[0048] like Figure 1 and Figure 2 As shown, for Figure 1 In the unidirectional ESD device 20 on the left side of the center, the first active region 6, body region 5, intrinsic epitaxial layer 3, epitaxial layer 2, and substrate 1 in the first region 21 can form a first low-capacitance diode D11. The second active region 7, intrinsic epitaxial layer 3, and buried layer 4 in the second region 22 can form a second low-capacitance diode D21. The buried layer 4, epitaxial layer 2, and substrate 1 in the second region 22 can form a first Zener diode Z11. The cathode of the first low-capacitance diode D1 is connected to the cathode of the Zener diode Z1, the anode of the first low-capacitance diode D1 is connected to the cathode of the second low-capacitance diode D2, and the anode of the second low-capacitance diode D2 is connected to the anode of the Zener diode Z1.

[0049] for Figure 1 In the unidirectional ESD device 20 on the middle right side, the first active region 6, body region 5, intrinsic epitaxial layer 3, epitaxial layer 2, and substrate 1 in the first region 21 can form a third low-capacitance diode D12. The second active region 7, intrinsic epitaxial layer 3, and buried layer 4 in the second region 22 can form a fourth low-capacitance diode D22. The buried layer 4, epitaxial layer 2, and substrate 1 in the second region 22 can form a second Zener diode Z12. The cathode of the third low-capacitance diode D12 is connected to the cathode of the second Zener diode Z12, the anode of the third low-capacitance diode D12 is connected to the cathode of the fourth low-capacitance diode D22, and the anode of the fourth low-capacitance diode D22 is connected to the anode of the second Zener diode Z12.

[0050] like Figure 2As shown, the connection point between the cathode of the first low-capacitance diode D11 in the first unidirectional ESD device 21 and the cathode of the first voltage-stabilizing diode Z11 serves as the first input port IO1 of the bidirectional ESD device, and the connection point between the cathode of the third low-capacitance diode D12 in the second unidirectional ESD device 22 and the cathode of the second voltage-stabilizing diode Z12 serves as the second input port IO2 of the bidirectional ESD device. The connection point between the anode of the first low-capacitance diode D11 in the first unidirectional ESD device 21 and the cathode of the second low-capacitance diode D21 is connected to the connection point between the anode of the third low-capacitance diode D12 and the cathode of the fourth low-capacitance diode D22 in the second unidirectional ESD device 22 to form a bidirectional ESD device.

[0051] The capacitance of the first unidirectional electrostatic discharge device 21 can be expressed as follows:

[0052] C1=C D11 +C D21

[0053] Wherein, C1 is the capacitance of the first unidirectional electrostatic discharge device 21, C D11 is the capacitance of the first low-capacitance diode D11, C D21 is the capacitance of the second low-capacitance diode D21.

[0054] The capacitance of the second unidirectional electrostatic discharge device 22 can be expressed as:

[0055] C2=C D12 +C D22

[0056] Wherein, C2 is the capacitance of the second unidirectional electrostatic discharge device 22, C D12 is the capacitance of the third low-capacitance diode D12, C D22 is the capacitance of the fourth low-capacitance diode D22.

[0057] The capacitance formula of a bidirectional ESD device is:

[0058]

[0059] Wherein, C is the capacitance of the bidirectional ESD device, C1 is the capacitance of the first unidirectional ESD device 21, and C2 is the capacitance of the second unidirectional ESD device 22. For example, the bidirectional ESD device provided in the embodiment of the present invention can achieve a self-capacitance of less than 0.2 pF.

[0060] Optionally, based on the above embodiments, continue to refer to Figure 1The unidirectional electrostatic discharge device 20 further includes a dielectric layer 11. The dielectric layer 11 is located between the intrinsic epitaxial layer 3 and the first conductive layer 8. The orthographic projection of the dielectric layer 11 on the substrate 1 covers the orthographic projection of the intrinsic epitaxial layer 3 on the substrate 1, the orthographic projection of the first active region 6 on the substrate 1, and the orthographic projection of the second active region 7 on the substrate 1. The first conductive layer 8 penetrates the dielectric layer 11 and is connected to the first active region 6 and the second active region 7.

[0061] Specifically, the dielectric layer 11 can be provided with a first through-groove and a second through-groove, and the first conductive layer 8 is provided on the side of the dielectric layer 11 away from the substrate 1, and extends to the first through-groove to connect with the first active area 6, and extends to the second through-groove to connect with the second active area 7. The dielectric layer 11 can include an insulating material such as silicon oxide. The bidirectional electrostatic discharge device provided by the embodiment of the utility model can effectively insulate the first conductive layer 2 from the intrinsic epitaxial layer 3 and the body region 5 by providing the dielectric layer 11, ensuring that the device can operate normally, thereby ensuring the reliability and stability of the device.

[0062] Optionally, based on the above embodiments, continue to refer to Figure 1 The unidirectional electrostatic discharge device 20 further includes a passivation layer 12 . Along the second direction X, the passivation layer 12 is located on both sides of the first conductive layer 8 ; the passivation layer 12 is used to physically protect the first conductive layer 8 .

[0063] Specifically, the passivation layer 12 may include insulating materials such as silicon oxide and silicon nitride. The passivation layer 12 is located on both sides of the first conductive layer 8 along a direction parallel to the plane of the substrate 1. The passivation layer 12 can protect the first conductive layer 8 and prevent the first conductive layer 8 from being scratched or water vapor intruding. The bidirectional electrostatic discharge device provided in the embodiment of the utility model effectively improves the reliability of the bidirectional electrostatic discharge device by setting the passivation layer 12.

[0064] Optionally, based on the above embodiments, continue to refer to Figure 1 The doping concentration of the buried layer 4 is less than that of the epitaxial layer 2. The doping type of the substrate 1 and the second active region 7 includes the first doping type, and the doping type of the epitaxial layer 2, the body region 5, the first active region 6 and the buried layer 4 includes the second doping type.

[0065] Specifically, the buried layer 4 can be a lightly doped silicon carbide buried layer or a gallium nitride buried layer of the second doping type, and the doping concentration of the buried layer 4 is lower than the doping concentration of the epitaxial layer 2. The buried layer 4 and the other film layers form a relatively wide spatial barrier region, which reduces the spatial barrier capacitance and further effectively reduces the parasitic capacitance of the bidirectional electrostatic discharge device. Exemplarily, the first doping type includes N-type, and the second doping type includes P-type, without any limitation herein.

[0066] Optionally, based on the above embodiments, continue to refer to Figure 1The intrinsic epitaxial layer 3 has a thickness of 10-20 μm and a resistivity greater than 100 Ω·cm. The substrate 1 has a thickness of 600-650 μm and a resistivity of 0.001-0.05 Ω·cm. The epitaxial layer 2 has a thickness of 4-10 μm and a resistivity of 1-10 Ω·cm.

[0067] Specifically, the technical solution of the embodiment of the utility model can set the thickness and doping concentration of different film layers according to actual needs, so that different film layers have specific resistivities. The thickness of the intrinsic epitaxial layer 3 can be set to 10-20μm, and the resistivity can be set to greater than 100Ω·cm. The thickness of the substrate 1 can be set to 600-650μm, and the resistivity can be set to 0.001-0.05Ω·cm. The thickness of the epitaxial layer 2 can be set to 4-10μm, and the resistivity can be set to 1-10Ω·cm.

[0068] If the intrinsic epitaxial layer 3, substrate 1, and epitaxial layer 2 are too thin, the device's withstand voltage performance will be reduced. If the intrinsic epitaxial layer 3, substrate 1, and epitaxial layer 2 are too thick, manufacturing difficulty will increase, production efficiency will decrease, and device performance will be affected. If the resistivity of the intrinsic epitaxial layer 3, substrate 1, and epitaxial layer 2 is too low, the device's withstand voltage performance will be reduced. If the resistivity of the intrinsic epitaxial layer 3, substrate 1, and epitaxial layer 2 is too high, the charge transfer rate and efficiency in the device will be affected, thereby affecting the overall performance of the device.

[0069] The embodiment of the present invention can achieve a self-capacitance of the bidirectional electrostatic discharge device of less than 0.2 pF by setting the thickness, doping concentration and other parameters of each film layer.

[0070] Figure 3 This is a flow chart of a method for preparing a bidirectional electrostatic discharge device provided by an embodiment of the present invention, such as Figure 3 As shown, the method includes:

[0071] S100: providing a substrate.

[0072] Specifically, such as Figure 4 As shown, firstly, a first substrate 1A and a second substrate 1B are provided. The first substrate 1A can be Figure 2 The substrate of the first unidirectional electrostatic discharge device 21, the second substrate 1B can be Figure 2 The substrate of the second unidirectional electrostatic discharge device 22. The semiconductor material of the first substrate 1A and the second substrate 1B can be silicon carbide or gallium nitride. The doping type of the first substrate 1A and the second substrate 1B is the first doping type and is heavily doped. For example, the first substrate 1A and the second substrate 1B can both be N+ substrates, with a (100) crystal orientation, a thickness of 600-650 μm, and a resistivity of 0.001-0.05 Ω·cm. Figure 1The substrate 1 includes a first substrate 1A or a second substrate 1B, Figure 1 The substrate 1 in the figure may be a first substrate 1A or a second substrate 1B.

[0073] S110: forming an epitaxial layer on one side of the substrate along a first direction, where the first direction is a thickness direction of the substrate.

[0074] Specifically, such as Figure 5 As shown, a first epitaxial layer 2A is epitaxially grown on one side of a first substrate 1A by a process such as chemical vapor epitaxy (CVE), molecular beam epitaxy (MBD) or atomic layer epitaxy (ALE), and a second epitaxial layer 2B is epitaxially grown on one side of a second substrate 1B. The first epitaxial layer 2A can be Figure 2 The epitaxial layer of the first unidirectional electrostatic discharge device 21, the second epitaxial layer 2B can be Figure 2 The first epitaxial layer 2A and the second epitaxial layer 2B may be lightly doped silicon carbide epitaxial layers or gallium nitride epitaxial layers of the second doping type. For example, the first epitaxial layer 2A and the second epitaxial layer 2B may both be P-epitaxial layers with a thickness of 4-10 μm and a resistivity of 1-10 Ω·cm. Figure 1 The epitaxial layer 2 includes a first epitaxial layer 2A or a second epitaxial layer 2B, Figure 1 The epitaxial layer 2 in the embodiment may be the first epitaxial layer 2A or the second epitaxial layer 2B.

[0075] S120: forming a buried layer along a first direction on a side of the epitaxial layer away from the substrate.

[0076] Specifically, such as Figure 6 As shown, an oxide layer is formed by injecting oxidation into the side of the first epitaxial layer 2A away from the first substrate 1A, and an oxide layer is formed by injecting oxidation into the side of the second epitaxial layer 2B away from the second substrate 1B. The oxidation temperature can be 900-1000°C / 100min, and the thickness of the formed oxide layer is The oxide layer is mainly used to protect the first epitaxial layer 2A and the second epitaxial layer 2B during the process of forming the first buried layer 4A and the second buried layer 4B. After the first buried layer 4A and the second buried layer 4B are formed, the oxide layer needs to be removed.

[0077] Along the first direction Y, a first buried layer 4A and a second buried layer 4B are formed by photolithography and implantation processes. The first buried layer 4A and the second buried layer 4B can be a lightly doped second doping type silicon carbide buried layer or a gallium nitride buried layer. The first buried layer 4A can be Figure 2 The buried layer of the first unidirectional electrostatic discharge device 21, the second buried layer 4B can be Figure 2The buried layer of the second unidirectional electrostatic discharge device 22 is formed. For example, the implanted element may be boron difluoride (BF2), the implantation dose may be 1E11-1E15, the implantation energy may be 30-90 KEV, and the diffusion temperature may be 1000°C-1200°C. Figure 1 The buried layer 4 includes a first buried layer 4A or a second buried layer 4B, Figure 1 The buried layer 4 in the embodiment may be the first buried layer 4A or the second buried layer 4B.

[0078] S130: forming an intrinsic epitaxial layer on a side of the epitaxial layer away from the substrate along a first direction; an orthographic projection of the intrinsic epitaxial layer on the substrate covers an orthographic projection of the buried layer on the substrate.

[0079] Specifically, such as Figure 7 As shown, along the first direction Y, a first intrinsic epitaxial layer 3A is epitaxially grown on the side of the first epitaxial layer 2A away from the first substrate 1A by chemical vapor phase epitaxy (CVE), molecular beam epitaxy (MBD) or atomic layer epitaxy (ALE) and a second intrinsic epitaxial layer 3B is epitaxially grown on the side of the second epitaxial layer 2B away from the second substrate 1B by chemical vapor phase epitaxy (CVE), molecular beam epitaxy (MBD) or atomic layer epitaxy (ALE). The first intrinsic epitaxial layer 3A can be Figure 2 The intrinsic epitaxial layer of the first unidirectional electrostatic discharge device 21, the second intrinsic epitaxial layer 3B can be Figure 2 The intrinsic epitaxial layer of the second unidirectional ESD device 22 is formed. The first intrinsic epitaxial layer 3A and the second intrinsic epitaxial layer 3B may be a silicon carbide intrinsic semiconductor or a gallium nitride intrinsic semiconductor. For example, the first intrinsic epitaxial layer 3A and the second intrinsic epitaxial layer 3B may have a thickness of 10-20 μm and a resistivity greater than 100 Ω·cm. Figure 1 The intrinsic epitaxial layer 3 includes a first intrinsic epitaxial layer 3A or a second intrinsic epitaxial layer 3B, Figure 1 The intrinsic epitaxial layer 3 in the embodiment may be a first intrinsic epitaxial layer 3A or a second intrinsic epitaxial layer 3B.

[0080] S140: Along a first direction, a body region, a first active region, and a second active region are formed on a side of the intrinsic epitaxial layer away from the substrate, wherein the first active region is located on a side of the body region away from the substrate; along a second direction, the second active region and the first active region are arranged on the same side; the second direction is a direction parallel to the plane of the substrate.

[0081] Specifically, such as Figure 8As shown, along the first direction Y, a first body region 5A is formed on the side of the first intrinsic epitaxial layer 3A away from the first substrate 1A through processes such as photolithography and implantation. The first body region 5A may be a lightly doped silicon carbide body region of the second doping type or a gallium nitride body region. A second body region 5B is formed on the side of the second intrinsic epitaxial layer 3B away from the second substrate 1B through processes such as photolithography and implantation. The second body region 5B may be a lightly doped silicon carbide body region of the second doping type or a gallium nitride body region. Exemplarily, the implanted element may be boron (B), with an implantation dose of 1E12-1E15 and an implantation energy of 30-90 KEV. Figure 1 The body region 5 in the embodiment includes a first body region 5A or a second body region 5B, Figure 1 The body region 5 in the embodiment may be the first body region 5A or the second body region 5B.

[0082] Along the first direction Y, a third active region 6A is formed on the side of the first body region 5A facing away from the first substrate 1A through processes such as photolithography and implantation. The third active region 6A may be a heavily doped silicon carbide active region or a gallium nitride active region of the second doping type. A fourth active region 6B is formed on the side of the second body region 5B facing away from the second substrate 1B through processes such as photolithography and implantation. The fourth active region 6B may be a heavily doped silicon carbide active region or a gallium nitride active region of the second doping type. Exemplarily, the implanted element may be boron (B), with an implantation dose of 1E12-1E15 and an implantation energy of 30-90 KEV. Figure 1 The first active region 6 includes the third active region 6A or the fourth active region 6B, Figure 1 The first active region 6 in the embodiment may be the third active region 6A or the fourth active region 6B.

[0083] Along the second direction X, a fifth active region 7A is formed on the same side of the third active region 6A through processes such as photolithography and implantation. The fifth active region 7A can be a heavily doped silicon carbide active region or a gallium nitride active region of the first doping type. A sixth active region 7B is formed on the same side of the fourth active region 6B through processes such as photolithography and implantation. The sixth active region 7B can be a heavily doped silicon carbide active region or a gallium nitride active region of the first doping type. Exemplarily, the implanted element can be boron (B), with an implantation dose of 1E12-1E15 and an implantation energy of 30-90 KEV. Figure 1 The second active region 7 includes the fifth active region 7A or the sixth active region 7B, Figure 1 The second active region 7 in the embodiment may be the fifth active region 7A or the sixth active region 7B.

[0084] After completing the above steps, annealing treatment is required, the temperature can be 1000° C.-1200° C., and the time can be 5-20 seconds.

[0085] The first body region 5A, the third active region 6A and the fifth active region 7A may be Figure 2 The body region, the first active region and the second active region of the first unidirectional electrostatic discharge device 21, the second body region 5B, the fourth active region 6B and the sixth active region 7B can be Figure 2 The body region, the first active region and the second active region of the second unidirectional electrostatic discharge device 22 are connected.

[0086] S150: forming a first conductive layer on a side of the intrinsic epitaxial layer away from the substrate along a first direction, the first conductive layer being connected to the first active area and the second active area respectively; and connecting two unidirectional electrostatic discharge devices through the first conductive layer.

[0087] Specifically, such as Figure 9 As shown, along the first direction Y, a third conductive layer 8A is formed on the side of the first intrinsic epitaxial layer 3A away from the first substrate 1A, and a fourth conductive layer 8B is formed on the side of the second intrinsic epitaxial layer 3B away from the second substrate 1B. For example, the third conductive layer 8A and the fourth conductive layer 8B can be formed by depositing aluminum silicon copper (AlSiCu). The third conductive layer 8A can be Figure 2 The first conductive layer of the first unidirectional electrostatic discharge device 21, the fourth conductive layer 8B can be Figure 2 The first conductive layer of the second unidirectional ESD device 22 is formed in the first conductive layer. The thickness of the third conductive layer 8A and the fourth conductive layer 8B can be 2-5 μm. The third conductive layer 8A of the first unidirectional ESD device 21 is connected to the fourth conductive layer 8B of the second unidirectional ESD device 22. The third conductive layer 8A and the fourth conductive layer 8B can be interconnected by wire bonding during device packaging. Figure 1 The first conductive layer 8 includes a third conductive layer 8A or a fourth conductive layer 8B, Figure 1 The first conductive layer 8 in the embodiment may be the third conductive layer 8A or the fourth conductive layer 8B.

[0088] S160: forming a second conductive layer on a side of the substrate away from the epitaxial layer along the first direction; the second conductive layer serves as an input port of the bidirectional electrostatic discharge device.

[0089] Specifically, such as Figure 1 As shown, before forming the second conductive layer 9, the side of the substrate 1 away from the epitaxial layer 2 needs to be thinned by mechanical grinding. The substrate 1 can be thinned to a thickness of 100-200um. Then, along the first direction Y, the second conductive layer 9 is formed by evaporation on the side of the substrate 1 away from the epitaxial layer 2. An exemplary second conductive layer 9 can be a titanium-nickel-silver alloy. The input port of the bidirectional electrostatic discharge device includes a first input port IO1 and a second input port IO2, wherein the second conductive layer 9 of one unidirectional electrostatic discharge device 20 serves as the first input port IO1, and the second conductive layer 9 of the other unidirectional electrostatic discharge device 20 serves as the second input port IO2. The second conductive layer 9 is wired out to form a bidirectional electrostatic discharge device.

[0090] According to the technical solution of the embodiment of the present utility model, an intrinsic epitaxial layer with high resistivity is provided in the bidirectional electrostatic discharge device. The width of the spatial barrier region formed by the intrinsic epitaxial layer and other film layers is relatively large, so that the barrier capacitance is relatively small, thereby effectively reducing the parasitic capacitance of the bidirectional electrostatic discharge device. At the same time, the bidirectional electrostatic discharge device is formed by two unidirectional electrostatic discharge devices connected in series. The series connection method can further effectively reduce the overall capacitance of the bidirectional electrostatic discharge device. The technical solution of the embodiment of the present utility model effectively reduces the capacitance value of the bidirectional electrostatic discharge device while ensuring that the bidirectional electrostatic discharge device has sufficiently large ESD robustness, thereby effectively improving the performance and reliability of the radio frequency circuit.

[0091] Optionally, based on the above embodiments, Figure 10 This is a flow chart of another method for preparing a bidirectional electrostatic discharge device provided by an embodiment of the present invention, such as Figure 10 As shown, the method includes:

[0092] S200: providing a substrate.

[0093] S210: forming an epitaxial layer on one side of a substrate along a first direction, where the first direction is a thickness direction of the substrate.

[0094] S220: forming a buried layer along a first direction on a side of the epitaxial layer away from the substrate.

[0095] S230: forming an intrinsic epitaxial layer on a side of the epitaxial layer away from the substrate along a first direction; an orthographic projection of the intrinsic epitaxial layer on the substrate covers an orthographic projection of the buried layer on the substrate.

[0096] S240: Along a first direction, a body region, a first active region, and a second active region are formed on a side of the intrinsic epitaxial layer away from the substrate, wherein the first active region is located on a side of the body region away from the substrate; along a second direction, the second active region and the first active region are arranged on the same side; the second direction is a direction parallel to the plane of the substrate.

[0097] S250: forming an isolation structure, wherein the isolation structure penetrates the intrinsic epitaxial layer and the epitaxial layer and extends to the substrate; along the second direction, the isolation structure divides the intrinsic epitaxial layer, the epitaxial layer and the substrate into a first region and a second region; the body region and the first active region are located in the first region; the second active region and the buried layer are located in the second region.

[0098] Specifically, such as Figure 11As shown, after forming the first body region 5A, the third active region 6A and the fifth active region 7A, a trench of the first isolation structure 10A is formed in the first intrinsic epitaxial layer 3A, the first epitaxial layer 2A and the first substrate 1A by processes such as photolithography. After forming the second body region 5B, the fourth active region 6B and the sixth active region 7B, a trench of the second isolation structure 10B is formed in the second intrinsic epitaxial layer 3B, the second epitaxial layer 2B and the second substrate 1B by processes such as photolithography. The width of the trenches of the first isolation structure 10A and the second isolation structure 10B can be 0.5-2um and the depth can be 10-35um. After forming the trenches, insulating materials such as silicon oxide are deposited in the trenches using furnace tube diffusion to form the first isolation structure 10A and the second isolation structure 10B. The first isolation structure 10A can be Figure 2 The isolation structure of the first unidirectional electrostatic discharge device 21, the second isolation structure 10B can be Figure 2 The isolation structure of the second unidirectional electrostatic discharge device 22 is shown. Figure 1 The isolation structure 10 includes a first isolation structure 10A or a second isolation structure 10B, Figure 1 The isolation structure 10 in the embodiment can be a first isolation structure 10A or a second isolation structure 10B. The bidirectional electrostatic discharge device provided by the embodiment of the utility model can avoid mutual interference between current and voltage signals in different regions of the device by providing the first isolation structure 10A and the second isolation structure 10B, thereby ensuring the reliability and stability of the device.

[0099] S260: forming a first conductive layer on a side of the intrinsic epitaxial layer away from the substrate along a first direction, wherein the first conductive layer is connected to the first active area and the second active area respectively; and two unidirectional electrostatic discharge devices are connected through the first conductive layer.

[0100] S270: forming a second conductive layer on a side of the substrate away from the epitaxial layer along the first direction; the second conductive layer serves as an input port of the bidirectional electrostatic discharge device.

[0101] Optionally, based on the above embodiments, Figure 12 This is a flow chart of another method for preparing a bidirectional electrostatic discharge device provided by an embodiment of the present invention, such as Figure 12 As shown, the method includes:

[0102] S300: providing a substrate.

[0103] S310: forming an epitaxial layer on one side of a substrate along a first direction, where the first direction is a thickness direction of the substrate.

[0104] S320: forming a buried layer along a first direction on a side of the epitaxial layer away from the substrate.

[0105] S330: forming an intrinsic epitaxial layer on a side of the epitaxial layer away from the substrate along a first direction; an orthographic projection of the intrinsic epitaxial layer on the substrate covers an orthographic projection of the buried layer on the substrate.

[0106] S340: Along a first direction, a body region, a first active region, and a second active region are formed on a side of the intrinsic epitaxial layer away from the substrate, wherein the first active region is located on a side of the body region away from the substrate; along a second direction, the second active region and the first active region are arranged on the same side; the second direction is a direction parallel to the plane where the substrate is located.

[0107] S350: forming an isolation structure, wherein the isolation structure penetrates the intrinsic epitaxial layer and the epitaxial layer and extends to the substrate; along the second direction, the isolation structure divides the intrinsic epitaxial layer, the epitaxial layer and the substrate into a first region and a second region; the body region and the first active region are located in the first region; the second active region and the buried layer are located in the second region.

[0108] S360: Along the first direction, a dielectric layer is formed on a side of the intrinsic epitaxial layer away from the substrate, the orthographic projection of the dielectric layer on the substrate covers the orthographic projection of the intrinsic epitaxial layer on the substrate, the orthographic projection of the first active area on the substrate, and the orthographic projection of the second active area on the substrate, and the first conductive layer penetrates the dielectric layer and is connected to the first active area and the second active area.

[0109] For details, please refer to Figure 11 In S350, while using furnace tube diffusion to deposit insulating materials such as silicon oxide in the grooves, insulating materials such as silicon oxide are deposited on the side of the first intrinsic epitaxial layer 3A away from the first substrate 1A to form a first dielectric layer 11A, and insulating materials such as silicon oxide are deposited on the side of the second intrinsic epitaxial layer 3B away from the second substrate 1B to form a second dielectric layer 11B. Then, photolithography and dry etching processes are used to form a first through-groove and a second through-groove on the first dielectric layer 11A, and photolithography and dry etching processes are used to form a third through-groove and a fourth through-groove on the second dielectric layer 11B. The third conductive layer 8A is provided on the side of the first dielectric layer 11A away from the first substrate 1A, and extends to the first through-groove to connect with the third active area 6A, and extends to the second through-groove to connect with the fifth active area 7A. The fourth conductive layer 8B is provided on the side of the second dielectric layer 11B away from the second substrate 1B, and extends to the third through-groove to connect with the fourth active area 6B, and extends to the fourth through-groove to connect with the sixth active area 7B. The first dielectric layer 11A can be Figure 2 The dielectric layer of the first unidirectional electrostatic discharge device 21, the second dielectric layer 11B can be Figure 2 The dielectric layer of the second unidirectional electrostatic discharge device 22. Figure 1 The dielectric layer 11 in the embodiment includes a first dielectric layer 11A or a second dielectric layer 11B. Figure 1The dielectric layer 11 in the embodiment of the present invention can be the first dielectric layer 11A or the second dielectric layer 11B. The bidirectional electrostatic discharge device provided by the embodiment of the present invention can effectively insulate the first conductive layer from the intrinsic epitaxial layer and the body region by providing a dielectric layer, thereby ensuring the normal operation of the device and thus ensuring the reliability and stability of the device.

[0110] S370: forming a first conductive layer on a side of the intrinsic epitaxial layer away from the substrate along a first direction, wherein the first conductive layer is connected to the first active region and the second active region respectively; and two unidirectional electrostatic discharge devices are connected through the first conductive layer.

[0111] S380: forming a second conductive layer on a side of the substrate away from the epitaxial layer along the first direction; the second conductive layer serves as an input port of the bidirectional electrostatic discharge device.

[0112] Optionally, based on the above embodiments, Figure 13 This is a flow chart of another method for preparing a bidirectional electrostatic discharge device provided by an embodiment of the present invention, such as Figure 13 As shown, the method includes:

[0113] S400: providing a substrate.

[0114] S410: forming an epitaxial layer on one side of a substrate along a first direction, where the first direction is a thickness direction of the substrate.

[0115] S420: forming a buried layer along a first direction on a side of the epitaxial layer away from the substrate.

[0116] S430: forming an intrinsic epitaxial layer on a side of the epitaxial layer away from the substrate along a first direction; an orthographic projection of the intrinsic epitaxial layer on the substrate covers an orthographic projection of the buried layer on the substrate.

[0117] S440: Along a first direction, a body region, a first active region, and a second active region are formed on a side of the intrinsic epitaxial layer away from the substrate, wherein the first active region is located on a side of the body region away from the substrate; along a second direction, the second active region and the first active region are arranged on the same side; the second direction is a direction parallel to the plane of the substrate.

[0118] S450: forming an isolation structure, wherein the isolation structure penetrates the intrinsic epitaxial layer and the epitaxial layer and extends to the substrate; along the second direction, the isolation structure divides the intrinsic epitaxial layer, the epitaxial layer and the substrate into a first region and a second region; the body region and the first active region are located in the first region; the second active region and the buried layer are located in the second region.

[0119] S460: Along the first direction, a dielectric layer is formed on a side of the intrinsic epitaxial layer away from the substrate, the orthographic projection of the dielectric layer on the substrate covers the orthographic projection of the intrinsic epitaxial layer on the substrate, the orthographic projection of the first active area on the substrate, and the orthographic projection of the second active area on the substrate, and the first conductive layer penetrates the dielectric layer and is connected to the first active area and the second active area.

[0120] S470: forming a first conductive layer on a side of the intrinsic epitaxial layer away from the substrate along a first direction, wherein the first conductive layer is connected to the first active region and the second active region respectively; and two unidirectional electrostatic discharge devices are connected through the first conductive layer.

[0121] S480: forming a passivation layer on both sides of the first conductive layer along the second direction; the passivation layer is used to physically protect the first conductive layer.

[0122] Specifically, such as Figure 14 As shown, along the second direction X, a first passivation layer 12A is formed on both sides of the third conductive layer 8A, and a second passivation layer 12B is formed on both sides of the fourth conductive layer 8B. Silicon nitride and silicon oxide can be deposited on the side of the third conductive layer 8A away from the first substrate 1A by chemical vapor deposition to form the first passivation layer 12A, and then the first passivation layer 12A on the surface of the third conductive layer 8A can be etched away by processes such as photolithography and dry etching. Silicon nitride and silicon oxide can be deposited on the side of the fourth conductive layer 8B away from the second substrate 1B by chemical vapor deposition to form the second passivation layer 12B, and then the second passivation layer 12B on the surface of the fourth conductive layer 8B can be etched away by processes such as photolithography and dry etching. The first passivation layer 12A can be Figure 2 The passivation layer of the first unidirectional electrostatic discharge device 21, the second passivation layer 12B can be Figure 2 The passivation layer of the second unidirectional electrostatic discharge device 22 is formed. Figure 1 The passivation layer 12 includes a first passivation layer 12A or a second passivation layer 12B, Figure 1 The passivation layer 12 can be a first passivation layer 12A or a second passivation layer 12B. The first passivation layer 12A and the second passivation layer 12B can protect the third conductive layer 8A and the fourth conductive layer 8B, preventing the third conductive layer 8A and the fourth conductive layer 8B from being scratched or having water vapor intrusion. The bidirectional electrostatic discharge device provided by the embodiment of the utility model effectively improves the reliability of the bidirectional electrostatic discharge device by providing the first passivation layer 12A and the second passivation layer 12B.

[0123] S490: forming a second conductive layer on a side of the substrate away from the epitaxial layer along the first direction; the second conductive layer serves as an input port of the bidirectional electrostatic discharge device.

[0124] An embodiment of the present invention provides a radio frequency port device, wherein the radio frequency port device includes the bidirectional electrostatic discharge device provided by any of the above embodiments, and has the beneficial effects of the bidirectional electrostatic discharge device provided by any of the above embodiments of the present invention.

[0125] It should be understood that the various forms of the processes shown above can be used to reorder, add, or delete steps. For example, the steps described in this utility model can be performed in parallel, sequentially, or in a different order, as long as the desired results of the technical solution of this utility model can be achieved. This is not limited herein.

[0126] The above specific embodiments do not limit the scope of protection of this utility model. Those skilled in the art will appreciate that various modifications, combinations, sub-combinations, and substitutions may be made based on design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model shall be included within the scope of protection of this utility model.

Claims

1. A bidirectional electrostatic discharge device, characterized in that: The invention comprises two unidirectional electrostatic discharge devices connected in series; the unidirectional electrostatic discharge device comprises: substrate; an epitaxial layer disposed on one side of the substrate along a first direction, wherein the first direction is a thickness direction of the substrate; a buried layer disposed on a side of the epitaxial layer away from the substrate along the first direction; An intrinsic epitaxial layer is provided on a side of the epitaxial layer away from the substrate along the first direction; the orthographic projection of the intrinsic epitaxial layer on the substrate covers the orthographic projection of the buried layer on the substrate; Along the first direction, the body region, the first active region, and the second active region are arranged on the side of the intrinsic epitaxial layer away from the substrate, wherein the first active region is located on the side of the body region away from the substrate; along the second direction, the second active region and the first active region are arranged on the same side; the second direction is a direction parallel to the plane of the substrate; a first conductive layer disposed on a side of the intrinsic epitaxial layer away from the substrate along the first direction, the first conductive layer being connected to the first active region and the second active region respectively; and the two unidirectional electrostatic discharge devices being connected via the first conductive layer; A second conductive layer is provided on a side of the substrate away from the epitaxial layer along the first direction; the second conductive layer serves as an input port of the bidirectional electrostatic discharge device.

2. The bidirectional electrostatic discharge device according to claim 1, characterized in that: The unidirectional electrostatic discharge device further includes: an isolation structure; The isolation structure penetrates the intrinsic epitaxial layer and the epitaxial layer and extends to the substrate. Along the second direction, the isolation structure divides the intrinsic epitaxial layer, the epitaxial layer and the substrate into a first region and a second region; The body region and the first active region are located in the first area; the second active region and the buried layer are located in the second area.

3. The bidirectional electrostatic discharge device according to claim 1, characterized in that: The unidirectional electrostatic discharge device further includes: a dielectric layer; The dielectric layer is located between the intrinsic epitaxial layer and the first conductive layer. The orthographic projection of the dielectric layer on the substrate covers the orthographic projection of the intrinsic epitaxial layer on the substrate, the orthographic projection of the first active area on the substrate, and the orthographic projection of the second active area on the substrate. The first conductive layer penetrates the dielectric layer and is connected to the first active area and the second active area.

4. The bidirectional electrostatic discharge device according to claim 1, characterized in that: The unidirectional electrostatic discharge device further comprises: a passivation layer; Along the second direction, the passivation layer is located on both sides of the first conductive layer; the passivation layer is used for physically protecting the first conductive layer.

5. The bidirectional electrostatic discharge device according to claim 1, characterized in that: The doping concentration of the buried layer is less than the doping concentration of the epitaxial layer; the doping types of the substrate and the second active region include a first doping type, and the doping types of the epitaxial layer, the body region, the first active region and the buried layer include a second doping type.

6. The bidirectional electrostatic discharge device according to claim 1, characterized in that: The thickness of the intrinsic epitaxial layer is 10-20 μm, and the resistivity is greater than 100 Ω·cm; the thickness of the substrate is 600-650 μm, and the resistivity is 0.001-0.05 Ω·cm; the thickness of the epitaxial layer is 4-10 μm, and the resistivity is 1-10 Ω·cm.

7. A radio frequency port device, characterized in that: The bidirectional electrostatic discharge device comprises the bidirectional electrostatic discharge device according to any one of claims 1 to 6.

Images