A bidirectional switch and electronic device

Abstract

The application provides a bidirectional switch and an electronic device, the bidirectional switch comprising: a substrate, an active layer arranged on the substrate, and a barrier layer arranged on the active layer; a first gate, a second gate, a first source and a second source arranged on a first surface of the barrier layer; at least one layer of metal field plate structure, each layer of the at least one layer of metal field plate structure comprising a first field plate and a second field plate, a first end of the first field plate being electrically connected to the first source, and a second end of the second field plate being electrically connected to the second source; and a pedestal arranged between the first surface of the barrier layer, the first gate and the second gate, a projection of the pedestal on a first plane at least partially overlapping a projection of the metal field plate structure on the first plane, the first plane being a plane on which the first surface is located. The pedestal can fill electron traps, reduce the capture of electrons by the material, reduce the electric field peak between the first gate and the second gate, and achieve electric field balance.

Description

Technical Field

[0001] This application relates to the field of semiconductor technology, and more specifically, to a bidirectional switch and electronic device. Background Technology

[0002] With the development of semiconductor technology, bidirectional switches have become an ideal choice for AC control, energy conversion, and high-frequency power electronics due to their bidirectional conduction capability, high efficiency, low loss, and simple structure. The application of bidirectional switches has been further expanded with the popularization of wide-bandgap semiconductors (such as silicon carbide or gallium nitride). However, bidirectional switches still suffer from uneven electric field distribution in high-frequency and high-voltage scenarios, leading to risks such as localized breakdown, thermal runaway, or shortened lifespan.

[0003] Therefore, how to achieve electric field balance in bidirectional switches is an urgent problem to be solved. Summary of the Invention

[0004] This application provides a bidirectional switch and electronic device, which can achieve electric field balancing of the bidirectional switch through the setting of the base.

[0005] In a first aspect, a bidirectional switch is provided, comprising: a substrate, an active layer disposed on the substrate, and a barrier layer disposed on the active layer; a first gate, a second gate, a first source, and a second source disposed on a first surface of the barrier layer, the first gate being disposed between the first source and the second gate, and the second gate being disposed between the first gate and the second source; at least one metal field plate structure, each metal field plate structure comprising a first field plate and a second field plate, a first end of the first field plate being electrically connected to the first source, and a second end of the second field plate being electrically connected to the second source; and a base disposed between the first surface of the barrier layer, the first gate, and the second gate, wherein the projection of the base onto a first plane at least partially overlaps with the projection of the metal field plate structure onto a first plane, the first plane being the plane containing the first surface.

[0006] It should be noted that the first surface in the embodiments of this application is the upper surface or the front surface. For example, "the first gate, the second gate, the first source and the second source disposed on the first surface of the barrier layer" can be understood as: the lower surfaces of the first gate, the second gate, the first source and the second source are in direct contact with the upper surface of the barrier layer; or it can also be understood as: there may be other layers between the barrier layer and the first gate, the second gate, the first source and / or the second source.

[0007] Optionally, the bidirectional switch may also include a buffer layer disposed between the substrate and the active layer, a nucleation layer disposed between the substrate and the buffer layer, a passivation layer disposed on the barrier layer (such as the surface of the barrier layer), and / or a spacer layer disposed on the barrier layer (which may at least partially cover the first gate and the second gate).

[0008] It should be understood that high voltage or high frequency switching conditions can significantly increase the dynamic on-resistance of bidirectional switches. Surface states and buffer layer traps can both cause charge trapping in the two-dimensional electron gas, resulting in a decrease in output current (i.e., current collapse) and affecting the conductivity of the device. Compared to traditional bidirectional switches, the bidirectional switch proposed in this application adds a base between the two gates. The base can fill electron traps, reducing the material's capture of electrons and thus reducing the electric field spike between the first and second gates. This improves the device's withstand voltage and reduces the impact of dynamic collapse, making devices (e.g., chips) including this bidirectional switch more reliable and cost-competitive.

[0009] In conjunction with the first aspect, in some implementations of the first aspect, the bidirectional switch includes an N-layer metal field plate structure, wherein the projection of the base onto a first plane at least partially overlaps with the projection of the metal field plate structure onto the first plane, comprising: the base including a first base and a second base, the first base being disposed at a first position, and the second base being disposed at a second position, the first position being a region on the first surface of the barrier layer below the second end of the first field plate in the i-th layer metal field plate structure, and the second position being a region on the first surface of the barrier layer below the first end of the second field plate in the i-th layer metal field plate structure, wherein N is a positive integer, and i is a positive integer less than or equal to N.

[0010] It should be noted that the second end of the first field plate is the end of the first field plate away from the source (that is, the end close to the region between the two gates), and the first end of the second field plate is the end of the second field plate away from the source (that is, the end close to the region between the two gates).

[0011] In addition, a first base and a second base can be provided for at least one layer of the N-layer metal field plate structure.

[0012] Based on the above scheme, the base set below the end of the field plate can lift the end of the field plate to form a step (when forming the field plate structure, since the base has already been formed below, the field plate structure is not deposited to form a plane, but will generate a step or protrusion along with the base). This step can reduce the electric field peaks below the field plate and improve the reliability of the device.

[0013] In conjunction with the first aspect, in some implementations of the first aspect, the base further includes at least one third base, each of the at least one third base being disposed in a third position, the third position not overlapping with the projection of the at least one layer of metal field plate structure onto the first plane.

[0014] It should be understood that the embodiments of this application do not limit the arrangement of the base. For example, it can be an aligned arrangement, an interlaced arrangement, or other arrangements that are partially aligned or completely misaligned.

[0015] Based on the above scheme, the addition of more bases can further reduce trap density, thereby reducing the current collapse effect. Furthermore, since the position of the third base can be flexibly set, it is better suited to specific applications of bidirectional switches. For example, the position of each third base can be determined according to the electric field strength in the access area (e.g., based on the electric field spikes presented in the access area, a third base can be placed near the corresponding spike to achieve electric field equalization at that spike).

[0016] In conjunction with the first aspect, in some implementations of the first aspect, the base includes a plurality of first bases and a plurality of second bases in the first direction.

[0017] Regarding the first direction, you can refer to... Figure 7 The relevant explanations are shown below.

[0018] Based on the above scheme, the arrangement of multiple first bases and multiple second bases can further reduce the trap density, thereby reducing the current collapse effect.

[0019] In conjunction with the first aspect, in some implementations of the first aspect, the first gate and the second gate are junction gates, the junction gate includes a gate electrode and a semiconductor structure, the substrate material includes junction-doped gallium nitride, the doping material includes magnesium, zinc, beryllium, cadmium or calcium, and the semiconductor structure of the substrate and the junction gate is formed by etching of the same layer material.

[0020] Based on the above approach, since the semiconductor structures of the base and the junction gate can be formed by etching the same layer of material, the semiconductor structure of the junction gate and the base can be fabricated using a single mask, thereby effectively reducing the fabrication cost of bidirectional switches (e.g., achieving the fabrication of the gate and base in one step reduces the complexity and time overhead of the bidirectional switch fabrication process). Furthermore, the same-layer structure can further compress space, allowing for higher integration density in bidirectional switches.

[0021] In conjunction with the first aspect, in some implementations of the first aspect, the material of the base includes silicon oxide, silicon nitride, or silicon oxynitride.

[0022] Based on the above scheme, a dielectric layer (the material of the dielectric layer includes silicon oxide, silicon nitride, or silicon oxynitride, etc.) can be formed on the barrier layer first, and then the dielectric layer can be etched to form a substrate (that is, a separate mask is required to realize the fabrication of the substrate), which provides a more flexible fabrication method for the substrate.

[0023] In conjunction with the first aspect, in some implementations of the first aspect, the projection shape of the base onto the first plane includes a rectangle, a square, a circle, an ellipse, a spindle shape, and / or a polygon.

[0024] Based on the above scheme, the projection shape of the base on the first plane has great flexibility and is easy to adapt to industrial design and production.

[0025] In conjunction with the first aspect, in some implementations of the first aspect, the bidirectional switch further includes: a dielectric layer disposed between the barrier layer and at least one field plate structure, the dielectric layer enclosing the base, and the material of the dielectric layer including silicon oxide, silicon nitride, or silicon oxynitride.

[0026] Based on the above scheme, the base can form a multi-level capacitor network with the semiconductor surface through the dielectric layer, attracting or repelling surface charges step by step, so that the depletion region expands more uniformly laterally.

[0027] In conjunction with the first aspect, in some implementations of the first aspect, the bidirectional switch is a nitrogen-based bidirectional switch, the active layer is a nitrogen-based active layer, and the barrier layer is a nitrogen-based barrier layer.

[0028] In one possible implementation, gallium nitride (GaN) is epitaxially grown on a substrate. In order to achieve a high-quality GaN layer, aluminum nitride (AlN), aluminum gallium nitride (AlGaN), and a buffer layer of GaN can be grown before epitaxial growth of GaN to relieve stress and reduce dislocations.

[0029] In conjunction with the first aspect, in some implementations of the first aspect, the distance between two adjacent bases in the base is greater than or equal to 0.1 micrometers and less than or equal to 10 micrometers.

[0030] In a second aspect, a method for fabricating a bidirectional switch is provided, the method comprising: forming an active layer on a substrate; forming a barrier layer on the active layer; forming a first gate, a second gate, a first source, a second source, and a base on a first surface of the barrier layer, wherein the first gate is disposed between the first source and the second gate, the second gate is disposed between the first gate and the second source, and the base is disposed between the first gate and the second gate, wherein the projection of the base onto a first plane at least partially overlaps with the projection of a metal field plate structure onto a first plane, the first plane being the plane on which the first surface is located; forming at least one metal field plate structure on the barrier layer, each metal field plate structure comprising a first field plate and a second field plate, one end of the first field plate being electrically connected to the first source, and one end of the second field plate being electrically connected to the second source.

[0031] In conjunction with the second aspect, in some implementations of the second aspect, the first gate and the second gate are junction gates, the junction gate including a gate electrode and a semiconductor structure, forming the first gate, the second gate, the first source, the second source and the base on a first surface of the barrier layer, including: forming a semiconductor layer on the barrier layer; patterning the semiconductor layer to form the semiconductor structure of the first gate, the semiconductor structure of the second gate and the base, the material of the semiconductor layer including junction-doped gallium nitride, the doping material including magnesium, zinc, beryllium, cadmium or calcium.

[0032] In conjunction with the second aspect, in certain implementations of the second aspect, forming a first gate, a second gate, a first source, a second source, and a base on a first surface of the barrier layer includes: forming the first gate, the second gate, the first source, and the second source on the barrier layer; forming a dielectric layer on the barrier layer; and patterning the dielectric layer to form a base, wherein the material of the dielectric layer includes silicon oxide, silicon nitride, or silicon oxynitride.

[0033] Based on the two implementation methods of the second aspect, a more flexible fabrication method for the base is provided.

[0034] It should be noted that the beneficial effects of the second aspect and its corresponding implementation can be further described in the relevant description of the first aspect and its corresponding implementation, which will not be elaborated here.

[0035] Thirdly, an electronic device is provided, including a driving circuit, a filtering circuit, a control circuit, a power conversion circuit, and at least one bidirectional switch comprising any possible implementation of the first aspect.

[0036] For example, the electronic device may be at least one of an inverter (such as a photovoltaic microinverter) and its energy storage system, an AC-AC motor drive, and / or a matrix converter. Attached Figure Description

[0037] Figure 1 This is a schematic diagram of a traditional transistor and a bidirectional switch.

[0038] Figure 2 This is a schematic diagram of the system architecture applicable to the embodiments of this application.

[0039] Figure 3 This is a structural schematic diagram of a bidirectional switch 300 applicable to an embodiment of this application.

[0040] Figure 4 This is a schematic diagram showing the positional relationship between the field plate and the base applicable to embodiments of this application.

[0041] Figure 5 This is a schematic diagram of the structure of the bidirectional switch 300A applicable to the embodiments of this application.

[0042] Figure 6 This is a structural schematic diagram of the bidirectional switch 300B applicable to embodiments of this application.

[0043] Figure 7 This is a schematic diagram of the structure of the bidirectional switch 300C applicable to embodiments of this application.

[0044] Figure 8 This is a schematic diagram of the shape of the base projected onto the first plane, applicable to embodiments of this application.

[0045] Figure 9 This is a schematic diagram of a method for preparing a bidirectional switch applicable to embodiments of this application. Detailed Implementation

[0046] The technical solutions of this application will now be described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort should fall within the scope of protection of this application.

[0047] To facilitate understanding of the embodiments of this application, the terms involved in this application will be briefly explained first.

[0048] 1. Bidirectional Switch (BDS)

[0049] A BDS (Block MOSFET) consists of two metal-oxide-semiconductor field-effect transistors connected in reverse series. It achieves bidirectional conduction (allowing current to flow in both forward and reverse directions), bidirectional blocking, and unidirectional conduction through a controlled gate. Its on / off state can be controlled by external signals (such as voltage or current). For example, when a control signal (such as gate voltage) is activated, the BDS allows current to flow in either direction; when the control signal is removed, the BDS blocks bidirectional current.

[0050] Figure 1 This is a schematic diagram of a traditional transistor and a bidirectional switch.

[0051] It should be understood that Figure 1 This is for illustrative purposes only and does not constitute a limitation on the structure of conventional transistors and bidirectional switches.

[0052] like Figure 1 As shown in (a), a conventional transistor includes a gate, a source, and a drain, and the breakdown voltage of the device is determined by the field plate combined with the region between the gate and the drain.

[0053] Optionally, the number of field plates depends on the voltage rating of the device, so the device may include any number of field plates, for example, it may include at least one field plate or none at all.

[0054] like Figure 1 As shown in (b), a BDS can include two gates and two sources, and the breakdown voltage of the device is determined by the area between the two gates combined with the field plates (such as S1FP1 and S2FP2). Unlike traditional transistors, BDS can handle bidirectional current without additional anti-parallel diodes, thereby reducing component count and circuit complexity. For example, BDS can eliminate the need for anti-parallel diodes, additional drive circuits, or isolation devices, reducing PCB area and cost. Furthermore, in complex topologies such as H-bridges and matrix converters, BDS can directly replace multiple sets of unidirectional switches, simplifying layout.

[0055] Furthermore, BDS, due to its low conduction loss characteristics (i.e., low on-resistance), can significantly reduce conduction losses in wide bandgap semiconductor devices such as silicon carbide (SiC) and gallium nitride (GaN).

[0056] In one implementation, the BDS may include a dual-gate transistor. This dual-gate transistor can be implemented using a pair of transistor elements connected in series, each transistor element including a source and a gate. When either gate is turned off, the transistor corresponding to that gate is turned off (i.e., charging or discharging operations can be terminated). In this case, the BDS may include at least one of the off transistor elements to act as a withstand voltage structure. If the withstand voltage provided by the BDS is sufficient, charging or discharging operations can be terminated to the BDS. However, if the withstand voltage provided by the BDS is poor, termination of charging or discharging operations to the BDS may fail, and the poor withstand voltage may be caused by breakdown in the BDS.

[0057] 2. Electric field equilibrium

[0058] Electric field equalization refers to the technique of uniformly distributing voltage or electric field across multiple devices or regions in power electronic systems or high-voltage equipment through design methods. Its core objective is to avoid localized electric field concentration (i.e., "electric field stress concentration"), thereby preventing device damage due to overvoltage and improving system reliability and efficiency.

[0059] Electric field imbalance may be caused by the following factors:

[0060] (1) Differences in device parameters: Even devices produced in the same batch may have slight differences in parasitic capacitance, threshold voltage or switching speed, resulting in uneven voltage distribution.

[0061] (2) Dynamic switching characteristics: During the switching transient process, the difference in the on / off time of the device will cause some devices to withstand higher instantaneous voltage.

[0062] (3) Asymmetrical layout: Asymmetrical distribution of PCB traces, parasitic inductance or capacitance may cause local concentration of electric field.

[0063] An imbalance in the electric field may lead to the following problems:

[0064] (1) Local breakdown: The voltage that the device withstands exceeds its rated value, causing avalanche breakdown or insulation failure.

[0065] (2) Thermal runaway: Devices in the high-voltage region overheat due to increased power consumption, which exacerbates parameter drift (such as an increase in on-resistance).

[0066] (3) Shortened lifespan: Electric field stress concentration accelerates device aging and reduces system reliability.

[0067] (4) Efficiency decline: Some devices enter the linear region due to overvoltage, resulting in increased conduction or switching losses.

[0068] Figure 2 This is a schematic diagram of the system architecture applicable to the embodiments of this application.

[0069] For ease of understanding, Figure 2 The application of BDS in a three-phase Vienna topology will be used as an example. A Vienna topology is a three-level rectifier consisting of three phase arms. A traditional three-phase Vienna topology comprises three unidirectional voltage sources and three load impedances, with each voltage source having a 120-degree phase difference. The three unidirectional voltage sources are connected to the center point of the three-phase transformer, and each load impedance is connected to the end of its respective phase. When the voltage sources and impedances in a three-phase Vienna topology are connected, three voltage waveforms are generated. When the phase of the voltage across the load impedance is the same as its resistance, the load impedance absorbs the maximum power, thus maximizing the generator output power of the three-phase Vienna topology.

[0070] like Figure 2 As shown, introducing BDS into the Vienna topology, replacing traditional unidirectional switches (such as IGBTs + diodes), enables bidirectional energy flow and more flexible topology reconfiguration. Specifically, each phase arm uses two BDS (or integrated BDS modules) to replace the original unidirectional switches and diodes. The bidirectional conduction of the BDS allows energy to flow from the grid to the load (rectification mode) or from the load to the grid (inverter mode), thereby reducing the number of diodes and lowering conduction losses to support regenerative braking energy feedback (such as electric vehicle charging stations) and / or integrated charging and discharging of energy storage systems.

[0071] It should be noted that, Figure 2This is merely one example of BDS being applied to a three-phase Vienna topology. Three-phase Vienna topologies incorporating BDS may also include other circuit structures and / or components, and the embodiments of this application do not limit this.

[0072] In one implementation, BDS can also be applied to power electronic converter systems. For example, in a matrix converter, BDS can function as a switching element, directly implementing AC-AC frequency conversion and voltage regulation without an intermediate DC link. This simplifies the topology, reduces switching losses, and enables high-frequency control algorithms (such as space vector modulation). As another example, in a dual active bridge (DAB), BDS can be used in high-frequency isolated DC-DC converters, supporting bidirectional energy transfer (such as energy exchange between batteries and the grid), thereby supporting soft-switching technology, dynamic power control strategies, and wide voltage range adaptation.

[0073] In one implementation, BDS can also be applied to motor drive and regenerative braking systems. For example, in an H-bridge motor drive circuit, BDS can replace the traditional "MOSFET + diode" combination, simplifying motor forward and reverse control, improving efficiency, and thus enabling integrated drive modules and sensorless control technology. As another example, in an electric vehicle regenerative braking system, BDS can be applied to energy recovery circuits to feed braking energy back to the battery, thereby enabling rapid switching control and / or multi-mode energy management.

[0074] In one implementation, BDS can also be applied to new energy and energy storage systems. For example, in photovoltaic inverters (PV Inverters), BDS can enable bidirectional energy flow between the DC and AC sides, supporting grid-fed and off-grid operation. As another example, in battery energy storage systems (BESS), BDS can be used for battery charge and discharge management, achieving seamless switching of charge and discharge paths, and can further realize multi-battery pack balancing control and / or fault isolation protection.

[0075] In one implementation, BDS can also be applied to solid-state circuit breakers. For example, in a solid-state circuit breaker (SSCB), BDS can serve as a fast switching element, supporting bidirectional fault current interruption (such as DC microgrid short-circuit protection), implementing ultra-fast shutdown algorithms and / or self-powered drive circuits.

[0076] In one implementation, BDS can also be applied to smart grids. For example, multi-port energy routers can be built based on BDS to flexibly allocate distributed energy resources and achieve multi-objective optimization control and / or dynamic topology reconfiguration.

[0077] It should be noted that the bidirectional switch in this application embodiment can be applied to any of the devices and / or systems shown above.

[0078] It should be understood that the system architecture and business scenarios described in the embodiments of this application are for the purpose of more clearly illustrating the technical solutions of the embodiments of this application, and do not constitute a limitation on the technical solutions provided in the embodiments of this application. As those skilled in the art will know, with the evolution of system architecture and the emergence of new business scenarios, the technical solutions provided in the embodiments of this application are also applicable to similar technical problems.

[0079] With the development of semiconductor technology, bandgap semiconductor devices (BDS) have become an ideal choice for AC control, energy conversion, and high-frequency power electronics due to their bidirectional conductivity, high efficiency, low loss, and simple structure. The application of BDS has been further expanded with the popularization of wide-bandgap semiconductors (such as silicon carbide or gallium nitride). However, in high-frequency and high-voltage scenarios, BDS still suffers from uneven electric field distribution, leading to risks such as localized breakdown, thermal runaway, or shortened lifespan.

[0080] For example, based on the traditional BDS structure, the distance between the two gates can be increased to balance the electric field, but this method will increase the cell design size of the BDS, affecting the chip's cost competitiveness and reliability.

[0081] In view of this, this application proposes a bidirectional switch that achieves electric field balance by setting electric field spikes in the base equalization device.

[0082] Figure 3 This is a structural schematic diagram of a bidirectional switch 300 applicable to an embodiment of this application.

[0083] like Figure 3 As shown, the bidirectional switch 300 includes a substrate, an active layer, a barrier layer, a first gate, a second gate, a first source, a second source, a metal field plate structure, and a base, which will be described in detail below.

[0084] It should be understood that Figure 3 The structural schematic diagram corresponds to the front view of the bidirectional switch 300. In other words, the structural schematic diagram reflects that the various components of the bidirectional switch 300 are formed in layers for viewing along a direction parallel to these layers.

[0085] It should be noted that the first surface in the embodiments of this application is the upper surface or the front surface. For example, "the first gate, the second gate, the first source, and the second source disposed on the first surface of the barrier layer" can be understood as: the first gate, the second gate, the first source, and the second source are disposed on the upper surface of the barrier layer, that is, the lower surfaces of the first gate, the second gate, the first source, and the second source are in direct contact with the upper surface of the barrier layer; or it can be understood as: the first gate, the second gate, the first source, and the second source are disposed on the front surface of the barrier layer, and the barrier layer can be directly connected to the first gate, the second gate, the first source, and / or the second source, or other layers may exist. For example, the first gate and the second gate can be junction gates. In one implementation, p-type GaN can also be disposed below the first gate and the second gate (i.e., above the barrier layer, or between the barrier layer and the first gate, or between the barrier layer and the second gate). This allows the p-type GaN layer below the gate to raise the barrier at the channel, thereby depleting the two-dimensional electron gas (2DEG) in the channel to achieve normally-off operation.

[0086] A substrate is disposed at the bottom layer of the bidirectional switch 300. The substrate can be a semiconductor, used to provide mechanical support for the semiconductor device and as a substrate for epitaxial growth. The substrate material can include silicon (Si), silicon germanium (SiGe), silicon carbide (SiC), gallium arsenide, p-type doped silicon, n-type doped silicon, sapphire, and / or semiconductor-on-insulator (e.g., silicon-on-insulator, SOI) etc.

[0087] Alternatively, the substrate material may also include group III elements, group IV elements, group V elements, or combinations thereof (e.g., group III-V compounds).

[0088] Optionally, the substrate may also include a doped region, a buried layer, an epitaxial (epi) layer, etc.

[0089] In one possible implementation, gallium nitride (GaN) can be epitaxially grown on the substrate surface (e.g., GaN as an active layer).

[0090] The active layer, disposed on the substrate, is a functional layer in semiconductor devices where key carrier behaviors (such as migration, recombination, and confined motion) occur. It can form heterojunctions or quantum structures with other layers (such as barrier layers or buffer layers) to achieve specific electrical or optical functions. The materials of the active layer can include nitrides or III-V compounds (such as GaN, aluminum nitride (AlN), and / or indium nitride (InN)).

[0091] Optionally, the active layer may include a channel layer, which forms a 2DEG with high electron mobility, serving as a conductive channel and the core region for carrier transport. For example, the active layer may be made of undoped GaN.

[0092] A barrier layer is disposed on the active layer to form a heterojunction with the active layer. It induces a 2DEG through piezoelectric polarization and spontaneous polarization effects, achieving high conductivity. The barrier layer material can include aluminum gallium nitride (AlGaN) and / or AlN, etc.

[0093] Alternatively, the materials of the active layer and the barrier layer can be selected such that the band gap (i.e., the forbidden band width) of the barrier layer is larger than that of the active layer. In this case, since the active layer and the barrier layer have different electron affinities, a heterojunction can be formed between them.

[0094] For example, the active layer is an undoped gallium nitride layer (band gap of approximately 3.4 eV), and the barrier layer is an AlGaN layer (band gap of approximately 4 eV). Due to the difference in their band gaps, a triangular well potential is generated at the interface between the active and barrier layers, causing electrons to accumulate in the triangular well potential, thereby generating a two-dimensional electron gas (2DEG) region adjacent to the heterojunction. Therefore, the bidirectional switch 300 may include at least one gallium nitride-based high-electron-mobility transistor (HEMT).

[0095] In one possible implementation, the bidirectional switch 300 is a nitrogen-based bidirectional switch, with its active layer being a nitrogen-based active layer and / or its barrier layer being a nitrogen-based barrier layer.

[0096] A first gate is disposed on the first surface of the barrier layer. The first gate structure may include a gate electrode #1 and a semiconductor layer #1 (e.g., a p-type doped III-V compound semiconductor layer). The semiconductor layer #1 and the gate electrode #1 are stacked sequentially on the first surface of the barrier layer (e.g., the semiconductor layer is disposed between the gate electrode and the barrier layer). Optionally, a dielectric layer may also be disposed on the semiconductor layer #1 and the gate electrode #1.

[0097] The second gate is also disposed on the first side of the barrier layer. The structure of the second gate is similar to that of the first gate (e.g., it may include gate electrode #2 and semiconductor layer #2). The embodiments of this application will not be described in detail here.

[0098] Optionally, the bidirectional switch 300 is an enhancement-mode device, which is normally-off when gate electrodes #1 and #2 are applied with approximately zero bias. Specifically, semiconductor layers #1 and #2 can form at least one pn junction with the barrier layer to deplete the 2DEG region, thereby causing at least a portion of the 2DEG region located below the first and second gates to have different characteristics (e.g., different electron concentrations) than the rest of the 2DEG region, and thus be blocked.

[0099] The first source electrode and the second source electrode are disposed on the first surface of the barrier layer, and the first source electrode and the second source electrode are respectively located on opposite sides of the first gate electrode and the second gate electrode (i.e., the first gate electrode is disposed between the first source electrode and the second gate electrode, and the second gate electrode is disposed between the first gate electrode and the second source electrode). The materials of the first source electrode and the second source electrode may include metals, alloys, doped semiconductor materials (e.g., doped crystalline silicon), compounds (e.g., silicides and nitrides), or other conductive materials. For example, they may be titanium (Ti), aluminum silicon (AlSi), and / or titanium nitride (TiN), etc. The first source electrode and the second source electrode may be a single layer or a multilayer with the same or different compositions, which is not limited in the embodiments of this application. The first source electrode and the second source electrode may be a single layer or a multilayer with the same or different compositions. In some embodiments, the first source electrode and the second source electrode may form an ohmic contact with the barrier layer.

[0100] It should be noted that, in Figure 3 In the illustrated structure, the source (first source and second source) can be symmetrical with respect to the gate (first gate and second gate); in some implementations, the source can also be asymmetrical with respect to the gate, which is not limited in this embodiment. The gate and source can together serve as a dual-gate transistor with a 2DEG region.

[0101] The bidirectional switch 300 further includes at least one layer of metal field plate structure. Each layer of the metal field plate structure includes a first field plate and a second field plate (the first and second field plates of each layer are arranged opposite to each other). One end of the first field plate is electrically connected to the first source, and one end of the second field plate is electrically connected to the second source. It should be understood that the metal field plate structure can affect the voltage of the electronic device. In some cases, the more layers of the metal field plate structure, the easier it is to regulate the voltage of the bidirectional switch 300. The embodiments of this application do not limit the number of layers of the metal field plate structure. It should be noted that when the bidirectional switch device 300 is in the off state, whether breakdown occurs in the region between the first gate and the second gate is related to the electric field distribution in that region. The material of the metal field plate can include conductive materials such as Ti, tantalum (Ta), TiN, and tantalum nitride (TaN), or aluminum, copper-doped silicon, and alloys including the above materials.

[0102] Alternatively, the material of the metal field plate may further include low-resistivity materials, such as polycrystalline silicon, silicon-chromium (Cr) compounds, etc.

[0103] Optionally, for metal field plate structures of different layers, the projections of the corresponding different first field plates on the first plane overlap at least partially, and the projections of the corresponding different second field plates on the first plane overlap at least partially, where the first plane is the plane containing the first surface of the barrier layer.

[0104] In one possible implementation, the projection of the upper metal field plate structure onto the first plane overlaps the projection of the lower metal field plate structure onto the first plane. In this case, the distance between the first and second field plates in the upper metal field plate structure is smaller than the distance between the first and second field plates in the lower metal field plate structure. Therefore, the electric field distribution in the region between the first and second gates can be suppressed (making the electric field distribution in the region between the first and second gates smooth) and avoiding electric field peaks.

[0105] Optionally, for metal field plate structures of different layers, the projections of the corresponding different first field plates on the first plane do not overlap, and the projections of the corresponding different second field plates on the first plane do not overlap.

[0106] It should be noted that for information regarding the structure, materials, and other related aspects of the substrate, active layer, barrier layer, gate, source, and metal field plate, further reference can be made to the descriptions in the prior art, which will not be repeated here in the embodiments of this application.

[0107] The bidirectional switch 300 also includes a base disposed on the first surface of the barrier layer and located between the first gate and the second gate, wherein the projection of the base on the first plane at least partially overlaps with the projection of the metal field plate structure on the first plane.

[0108] Alternatively, the substrate material may include junction-doped gallium nitride, with the doping material including magnesium, zinc, beryllium, cadmium, or calcium.

[0109] In this scenario, if the first and second gates are junction gates (a junction gate includes a gate electrode and a semiconductor structure), the semiconductor structure of the substrate and the junction gate can be formed by etching the same layer of material. That is, the semiconductor structure of the junction gate and the substrate can be fabricated using a single mask, effectively reducing the fabrication cost of the bidirectional switch. Furthermore, the same-layer structure can further compress space, allowing the bidirectional switch to have higher integration density.

[0110] Alternatively, the base material may include silicon oxide, silicon nitride, or silicon oxynitride.

[0111] In this case, a dielectric layer can be formed on the barrier layer first, and then the dielectric layer can be etched to form a substrate (i.e., a separate mask is needed to fabricate the substrate). The material of the dielectric layer includes silicon oxide, silicon nitride, or silicon oxynitride, etc.

[0112] It should be understood that high voltage or high frequency switching conditions may significantly increase the dynamic on-resistance of the bidirectional switch 300. Surface states and buffer layer traps can both cause charge trapping in the 2DEG (for example, a large number of defect states (surface states) on the surface of the barrier layer trap free electrons in the 2DEG under high electric fields, reducing the channel carrier concentration; or, for example, deep-level defects in the buffer layer (such as traps introduced by carbon doping) are activated under high voltage, generating stress through the inverse piezoelectric effect, exacerbating carrier scattering), thus causing a decrease in output current (i.e., current collapse), affecting the conductivity of the device. The base can fill the electron traps, reducing the material's trapping of electrons, thereby reducing the electric field spike between the first and second gates. This improves the device's breakdown voltage and reduces the impact of dynamic collapse, making devices (e.g., chips) including this bidirectional switch more reliable and cost-competitive.

[0113] In one possible implementation, the base can be positioned below the end of the field plate.

[0114] For example, the bidirectional switch 300 includes an N-layer metal field plate structure, and the projection of the base on a first plane at least partially overlaps with the projection of the metal field plate structure on the first plane. The base includes a first base and a second base, the first base is disposed at a first position, and the second base is disposed at a second position. The first position is the region on the first surface of the barrier layer below the second end of the first field plate in the i-th layer metal field plate structure, and the second position is the region on the first surface of the barrier layer below the first end of the second field plate in the i-th layer metal field plate structure. Here, N is a positive integer, and i is a positive integer less than or equal to N.

[0115] It should be noted that the second end of the first field plate is the end of the first field plate away from the source (that is, the end close to the region between the two gates), and the first end of the second field plate is the end of the second field plate away from the source (that is, the end close to the region between the two gates).

[0116] Furthermore, the embodiments of this application do not limit the provision of a base below the end of each metal field plate structure in the N-layer metal field plate structure (i.e., it does not limit the provision of a corresponding first base and second base for each metal field plate structure). In other words, a first base and a second base can be provided for at least one metal field plate structure in the N-layer metal field plate structure.

[0117] like Figure 4 As shown, the base set below the end of the field plate can lift the end of the field plate to form a step (when forming the field plate structure, since the base has already been formed below, the field plate structure is not deposited to form a plane, but will form a step or protrusion along with the base). This step can reduce the electric field peaks below the field plate and improve the reliability of the device.

[0118] Figure 5 This is a schematic diagram of the structure of the bidirectional switch 300A applicable to the embodiments of this application.

[0119] like Figure 5 As shown, the bidirectional switch 300A includes two layers of metal field plate structures (metal field plate structure #1 and metal field plate structure #2). A first base is provided in the area below the second end of the first field plate of each metal field plate structure (metal field plate structure #1 corresponds to the first base #1, and metal field plate structure #2 corresponds to the first base #2). A second base is provided in the area below the first end of the second field plate (metal field plate structure #1 corresponds to the second base #1, and metal field plate structure #2 corresponds to the second base #2).

[0120] It should be understood that Figure 5 This is for illustrative purposes only and does not constitute a limitation on the number of layers of the metal field plate structure, the number of metal field plate structures with a first base and a second base, or the number of the first base and the second base that the bidirectional switch may include in the embodiments of this application.

[0121] In another possible implementation, the base can be further positioned in an area not covered by the field plate.

[0122] For example, the base also includes at least one third base, each of the at least one third base being disposed in a third position, the third position not overlapping the projection of the at least one layer of metal field plate structure onto the first plane.

[0123] Figure 6This is a structural schematic diagram of the bidirectional switch 300B applicable to embodiments of this application.

[0124] like Figure 6 As shown, the bidirectional switch 300B includes two metal field plate structures (metal field plate structure #1 and metal field plate structure #2). A first base (corresponding to first base #1) is provided in the region below the second end of the first field plate of metal field plate structure #1, and a second base (corresponding to second base #1) is provided in the region below the first end of the second field plate of metal field plate structure #1. Neither the first base nor the second base is provided in the region below the second end of the second field plate of metal field plate structure #2. Furthermore, at least one third base is provided in the area not covered by the field plate. It should be understood that... Figure 6 This is for illustrative purposes only and does not constitute a limitation on the number of layers of the metal field plate structure, the number of metal field plate structures with a first base and a second base, or the number of the first base, second base, and third base that the bidirectional switch may include in the embodiments of this application.

[0125] It should be understood that the addition of more bases (such as a third base) can further reduce trap density, thereby reducing current collapse effects. Furthermore, since the location of the third bases can be flexibly configured, they are better suited to the specific applications of bidirectional switches. For example, the location of each third base can be determined based on the electric field strength in the access area (e.g., based on the electric field spikes presented in the access area, a third base can be placed near the corresponding spike to achieve electric field equalization at that spike).

[0126] It should be noted that since the first base, the second base and / or the third base included in the base are all independently disposed on the first surface of the barrier layer, the base can also be called a base island. The name of the base is not limited in the embodiments of this application, and the base is uniformly described in this application.

[0127] It should be understood that, in one possible implementation, the base can also be placed only in the area not covered by the field plate (i.e., the third position), thereby filling the electron trap to some extent and reducing the material's capture of electrons.

[0128] Optionally, the base can be distributed in a "dashed line" pattern in the first direction, which is perpendicular to the direction of the road. Figures 3-5 The direction of the plane (which can also be understood as the direction along the line of sight of the main view).

[0129] Figure 7 This is a schematic diagram of the structure of the bidirectional switch 300C applicable to embodiments of this application.

[0130] Figure 7 This is a top view of the 300C bidirectional switch. It should be understood that... Figure 7This is merely a possible illustration of the base distribution in a bidirectional switch and does not constitute a limitation on the number of metal field plate structures that the bidirectional switch in the embodiments of this application may include, the number of metal field plate structures with first and second bases, and the number and position of the first, second, and third bases.

[0131] For example, such as Figure 7 As shown in (a), the base of the bidirectional switch 300C may include a plurality of first bases and a plurality of second bases in the first direction. As a possible implementation, Figure 5 It can be Figure 7 Image (a) shows a cross-sectional view of the bidirectional switch 300A cut along cut-1. Figure 7 As shown in (b), the base of the bidirectional switch 300C may include a plurality of first bases, a plurality of second bases, and a plurality of third bases in the first direction. As a possible implementation, Figure 6 It can be Figure 7 (b) shows a cross-sectional view of the bidirectional switch 300A cut along cut-1.

[0132] In addition, due to Figure 7 The central base is distributed in a dotted line in the first direction, thus Figure 7 (a) shows the bidirectional switch 300C and / or Figure 7 The cross-sectional view of the bidirectional switch 300C shown in (b) along cut-2 may also exclude the base.

[0133] Figure 7 Images (a) and (b) are merely examples illustrating the aligned arrangement of multiple bases included in the bidirectional switch C from a top-view perspective (i.e., the multiple bases are aligned in rows and columns). It should be noted that the embodiments of this application do not limit the arrangement of the bases; for example, they can be aligned or staggered (e.g., ...). Figure 7 As shown in (c), the cross-sectional view of the bidirectional switch cut along cut-2 can also include only a portion of the bases in the entire base. ) and other partially aligned or completely misaligned arrangements. Partial alignment can be understood as the projections of the bases onto the second plane partially overlapping, while complete misalignment can be understood as the projections of the bases onto the second plane not overlapping at all. The second plane is a plane perpendicular to the first plane along the first direction.

[0134] Understandably, the addition of more bases (such as multiple first bases and multiple second bases in the first direction) can further reduce trap density, thereby reducing the current collapse effect.

[0135] Optionally, the projection of any base (such as one of the first bases, one of the second bases, or one of the third bases) onto the first plane may include a variety of shapes.

[0136] For example, such as Figure 8 As shown, the projection shape of the base on the first plane includes rectangles, squares, circles, ellipses, spindles and / or polygons, or may include other shapes.

[0137] Furthermore, the embodiments of this application do not limit the projection shape of each base in the bidirectional switch base to the same on the first plane.

[0138] It should also be noted that the embodiments of this application do not limit the size, spacing, material, or thickness of each base.

[0139] For example, the distance between two adjacent bases is greater than or equal to 0.1 micrometers and less than or equal to 10 micrometers. Two adjacent bases may include bases adjacent in a first direction and / or bases adjacent in a second direction (the second direction being parallel to...). Figures 5-6 The direction of the plane (which can also be understood as the direction of the line of sight along the side view).

[0140] For example, the size (i.e., length and / or width) of each base can also be greater than or equal to 0.1 micrometers and less than or equal to 10 micrometers.

[0141] Optionally, the bidirectional switch 300 may further include a dielectric layer disposed between the barrier layer and at least one field plate structure (including a metal field plate structure), the dielectric layer encapsulating the substrate, and the material of the dielectric layer including silicon oxide, silicon nitride, or silicon oxynitride. Optionally, in some implementations, the dielectric layer may also be a passivation layer and / or a spacer layer, as described below, and will not be repeated here.

[0142] In addition, the bidirectional switch 300 may also include other layers or structures, as can be seen from the relevant descriptions in the prior art, and the embodiments of this application are not limited thereto.

[0143] Optionally, the bidirectional switch 300 may also include a buffer layer. The buffer layer may be disposed between the substrate and the active layer to alleviate lattice mismatch between the substrate and the epitaxial layer (such as the active layer), reduce defects, and improve crystal quality. The material of the buffer layer may include GaN, AlN, AlGaN, and / or aluminum indium gallium nitride (InAlGaN), etc.

[0144] In one possible implementation, GaN is epitaxially grown on a substrate, and in order to achieve a high-quality GaN layer, a buffer layer of AlN, AlGaN, and GaN can be grown first before epitaxial growth of GaN to relieve stress and reduce dislocations.

[0145] Optionally, the bidirectional switch 300 may also include a nucleation layer. The nucleation layer may be disposed between the substrate and the buffer layer to accommodate (or transition) the mismatch / difference between the group III nitride layers of the substrate and the buffer layer. The material of the nucleation layer may include AlN and / or any alloy thereof.

[0146] Optionally, the bidirectional switch 300 may also include a passivation layer. The passivation layer may be disposed on the barrier layer (such as the surface of the barrier layer) to protect the surface and reduce interface states and current collapse effects. The material of the passivation layer may include SiN and / or SiO, etc.

[0147] Optionally, the bidirectional switch 300 may further include a spacer layer. The spacer layer may be disposed on a barrier layer and may at least partially cover the first gate and the second gate. The spacer layer may be used to protect the bidirectional switch 300, or it may be used to provide electrical isolation between different layers / elements to enhance the electrical characteristics of the device. The material of the spacer layer may include silicon nitride (SiNx), silicon oxide (SiOx), silicon nitride (Si3N4), silicon oxynitride (SiON), silicon carbide (SiC), silicon boron nitride (SiBN), silicon carbide boron carbide (SiCBN), oxides, and / or nitrides. Optionally, the spacer layer may also be a multilayer structure, thus being a composite dielectric layer comprising at least one material.

[0148] Figure 9 This is a schematic diagram of a method for preparing a bidirectional switch applicable to embodiments of this application.

[0149] based on Figure 9 The preparation method can yield any of the bidirectional switches shown above.

[0150] S901: An active layer is formed on the substrate.

[0151] For example, an active layer can be formed on the substrate surface by epitaxial growth (optionally, the active layer can be a nitrogen-based active layer, and the material of the active layer includes GaN).

[0152] S902: A barrier layer is formed on the active layer.

[0153] For example, a barrier layer can be formed on the surface of the active layer by epitaxial growth (optionally, the barrier layer can be a nitrogen-based barrier layer, and the material of the barrier layer includes AlGaN).

[0154] S903: A first gate, a second gate, a first source, a second source, and a base are formed on the first surface of the barrier layer.

[0155] Wherein, the first gate is disposed between the first source and the second gate, the second gate is disposed between the first gate and the second source, the base is disposed between the first gate and the second gate, and the projection of the base onto the first plane at least partially overlaps with the projection of the metal field plate structure onto the first plane, the first plane being the plane containing the first surface.

[0156] Optionally, the first gate and the second gate are junction gates (a junction gate includes a gate electrode and a semiconductor structure).

[0157] For example, source metal can be deposited using electron beam evaporation technology, and a low-resistance ohmic contact can be formed through rapid annealing. The first and second source electrodes are formed on opposite sides of the barrier layer, and the distance between the first and second source electrodes can be adjusted according to the device's voltage withstand requirements.

[0158] For example, after coating with photoresist, the gate region can be defined on the surface of the barrier layer using photolithography techniques (such as electron beam lithography or deep ultraviolet lithography). Specifically, for conventional HEMTs, gate metal can be deposited using electron beam evaporation to form a Schottky contact, thereby achieving an electric field-controlled 2DEG; for enhancement-mode HEMTs, a p-type GaN layer can be further epitaxially grown outside the gate region to form a pn junction gate, achieving normally-off characteristics.

[0159] Optionally, before forming the first and second gates, the barrier layer can be partially etched down to the active layer to enhance the gate's control over the 2DEG and reduce the threshold voltage. After etching, the gate metal can directly contact GaN to form a more efficient Schottky barrier and improve transconductance.

[0160] It should be noted that during the fabrication of the gate, the substrate can be formed simultaneously with the gate, or the gate and the substrate can be formed separately. The embodiments of this application do not limit the fabrication order of the substrate and the gate.

[0161] In one possible implementation, step S903, "forming a first gate, a second gate, a first source, a second source, and a base on the first surface of the barrier layer," can be implemented based on steps S903a-S903b.

[0162] S903a: A semiconductor layer is formed on the barrier layer.

[0163] The semiconductor layer is made of junction-doped gallium nitride (p-GaN), and the doping material includes magnesium, zinc, beryllium, cadmium or calcium.

[0164] For example, a semiconductor layer can be formed on the barrier layer by epitaxial growth techniques such as metal-organic chemical vapor deposition (MOCVD).

[0165] S903b: Pattern the semiconductor layer to form the semiconductor structure of the first gate, the semiconductor structure of the second gate, and the substrate.

[0166] It should be noted that for details regarding the first gate, second gate, first source, second source, and base, please refer to the preceding text. Figures 3-8 The relevant descriptions are not repeated here in the embodiments of this application. Furthermore, metal layer patterning includes locally processing or patterning the metal layer to achieve a patterned metal structure.

[0167] In this configuration, the semiconductor structures of the base and gate can be formed by etching the same layer of material. This allows for the fabrication of the junction gate semiconductor structure and the base based on a single mask, effectively reducing the fabrication cost of bidirectional switches. Furthermore, the same-layer structure can further compress space, enabling bidirectional switches to achieve higher integration density.

[0168] In another possible implementation, step S903, "forming a first gate, a second gate, a first source, a second source, and a base on the first surface of the barrier layer", can be implemented based on steps S903c-S903b.

[0169] S903c: A first gate, a second gate, a first source, and a second source are formed on the barrier layer.

[0170] S903d: A dielectric layer is formed on the barrier layer.

[0171] The dielectric layer is made of silicon oxide, silicon nitride, or silicon oxynitride.

[0172] For example, silicon oxides, silicon nitrides, or silicon oxynitrides can be deposited on the barrier layer using techniques such as chemical vapor deposition (CVD), atomic layer deposition (ALD), and plasma-enhanced chemical vapor deposition (PECVD) to form a dielectric layer.

[0173] S903e: Pattern the dielectric layer to form the base.

[0174] It should be understood that the difference between steps S903c-S903e and steps S903a-S903b is that the semiconductor structures of the substrate and the gate are formed independently, thus requiring a separate mask to fabricate the substrate.

[0175] S904: At least one layer of metal field plate structure is formed on the barrier layer.

[0176] Each of the at least one layer of metal field plate structure includes a first field plate and a second field plate, one end of the first field plate being electrically connected to the first source electrode, and one end of the second field plate being electrically connected to the second source electrode.

[0177] The materials for the metal field plate structure can include conductive materials such as Ti, Ta, TiN, and TaN, or aluminum, copper-doped silicon, and alloys containing the above materials. Optionally, the materials for the metal field plate structure can further include low-resistivity materials, such as polycrystalline silicon and silicon-chromium compounds.

[0178] For example, taking the fabrication of a single metal field plate structure as an example, the material of the metal field plate structure can be deposited by a deposition process (such as electron beam evaporation or sputtering) and the material can be patterned to form a first field plate and a second field plate.

[0179] It should also be noted that the fabrication process can be understood as sequentially covering the substrate surface with different materials to form different layers and layer structures. Therefore, if the lower layer structure does not cover the entire substrate surface, the upper layer structure may exhibit corresponding "undulations." For example, the upper metal field plate structure may appear as a "stepped" structure due to the presence of the lower substrate. In the embodiments of this application, different layers are used to indicate different layer structures formed during the fabrication process, and do not limit the "same layer" to necessarily being located on the same plane.

[0180] To facilitate understanding of the above embodiments provided in this application, the following points are made.

[0181] (1) In the various embodiments of this application, unless otherwise specified or logically conflicting, the terms and / or descriptions of different embodiments are consistent and can be referenced by each other. The technical features of different embodiments can be combined to form new embodiments according to their inherent logical relationship.

[0182] (2) In this application, "first" and "second" are used for descriptive convenience only to distinguish objects and are not intended to limit the scope of the embodiments of this application. They are not used to describe the order or sequence of features. It should be understood that the objects described in this way can be interchanged where appropriate so as to describe solutions other than those in the embodiments of this application.

[0183] (3) In this application, the words “exemplary,” “for example,” “exemplary,” “as another example,” etc., are used to indicate that they are examples, illustrations, or descriptions. Any embodiment or design that is described as an “exemplary” in this application should not be construed as being more preferred or advantageous than other embodiments or designs.

[0184] (4) In this application, “comprising,” “including,” “having,” and variations thereof mean “including but not limited to,” unless otherwise specifically emphasized. “At least one” means one or more, and “more” means two or more.

[0185] (5) In this application, "and / or" describes the relationship between related objects, indicating that there can be three relationships. For example, A and / or B can mean: A exists alone, A and B exist simultaneously, or B exists alone, where A and B can be singular or plural. The character " / " generally indicates that the related objects before and after are in an "or" relationship. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one of a, b, and c can mean: a, or, b, or, c, or, a and b, or, a and c, or, b and c, or, a, b, and c. Where a, b, and c can be single or multiple.

[0186] (6) Some optional features in the various embodiments of this application may not depend on other features in some scenarios, or may be combined with other features in some scenarios, without limitation.

[0187] (7) In this application, spatial descriptions, such as "above," "under," "upward," "left," "right," "below," "top," "bottom," "vertical," "horizontal," "one side," "above," "below," etc., are defined for a specific plane of a component or a group of components, and the orientation of the component can be shown in its corresponding figure. It should be understood that the spatial descriptions used herein are for illustrative purposes only, and the structure described herein can be arranged in space in any orientation or manner in practice, provided that the advantages of the embodiments of this application are not deviated from by such arrangement.

[0188] Furthermore, it should be noted that the actual shapes of various structures depicted as approximately rectangular may, in actual devices, be curved, have rounded edges, or have uneven thicknesses, due to manufacturing conditions. In this application, the use of straight lines and right angles is solely for the convenience of representing layers and technical features.

[0189] Those skilled in the art will understand that various changes can be made and equivalent solutions can be substituted without departing from the spirit and scope of this application. Furthermore, numerous modifications can be made to adapt specific circumstances, materials, material compositions, processes, or one or more process steps to the purpose, spirit, and scope of this application. All such modifications are intended to be within the scope of the appended claims.

[0190] Unless otherwise stated, all technical and scientific terms used in the embodiments of this application have the same meaning as commonly understood by one of ordinary skill in the art. The terminology used in this application is for the purpose of describing specific embodiments only and is not intended to limit the scope of this application. It should be understood that the above are illustrative examples, and the examples above are merely to help those skilled in the art understand the embodiments of this application, and are not intended to limit the embodiments of the application to the specific numerical values ​​or specific scenarios exemplified. Those skilled in the art can obviously make various equivalent modifications or variations based on the examples given above, and such modifications and variations also fall within the scope of the embodiments of this application.

[0191] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A bidirectional switch, characterized in that, include: A substrate, an active layer disposed on the substrate, and a barrier layer disposed on the active layer; A first gate, a second gate, a first source, and a second source are disposed on the first surface of the barrier layer, wherein the first gate is disposed between the first source and the second gate, and the second gate is disposed between the first gate and the second source; At least one layer of metal field plate structure, each layer of metal field plate structure including a first field plate and a second field plate, wherein a first end of the first field plate is electrically connected to the first source electrode, and a second end of the second field plate is electrically connected to the second source electrode; A base is disposed between the first surface of the barrier layer, the first gate, and the second gate. The projection of the base onto the first plane at least partially overlaps with the projection of the metal field plate structure onto the first plane, wherein the first plane is the plane containing the first surface.

2. The bidirectional switch according to claim 1, characterized in that, The bidirectional switch includes an N-layer metal field plate structure, wherein the projection of the base onto a first plane at least partially overlaps with the projection of the metal field plate structure onto the first plane, including: The base includes a first base and a second base. The first base is disposed at a first position, and the second base is disposed at a second position. The first position is the region below the second end of the first field plate in the i-th layer metal field plate structure on the first surface of the barrier layer. The second position is the region below the first end of the second field plate in the i-th layer metal field plate structure on the first surface of the barrier layer. Here, N is a positive integer, and i is a positive integer less than or equal to N.

3. The bidirectional switch according to claim 2, characterized in that, The base further includes at least one third base, each of the at least one third base being disposed at a third position, the third position not overlapping with the projection of the at least one layer of metal field plate structure onto the first plane.

4. The bidirectional switch according to claim 2 or 3, characterized in that, The base includes a plurality of first bases and a plurality of second bases in a first direction.

5. The bidirectional switch according to any one of claims 1 to 4, characterized in that, The first gate and the second gate are junction gates, each junction gate including a gate electrode and a semiconductor structure. The substrate material includes junction-doped gallium nitride, and the doping material includes magnesium, zinc, beryllium, cadmium, or calcium. The semiconductor structure of the substrate and the junction gate is formed by etching the same layer of material.

6. The bidirectional switch according to any one of claims 1 to 4, characterized in that, The base material includes silicon oxides, silicon nitrides, or silicon oxynitrides.

7. The bidirectional switch according to any one of claims 1 to 6, characterized in that, The projection shape of the base onto the first plane includes rectangle, square, circle, ellipse, spindle and / or polygon.

8. The bidirectional switch according to any one of claims 1 to 7, characterized in that, The bidirectional switch also includes: A dielectric layer is disposed between the barrier layer and the at least one field plate structure, the dielectric layer encapsulates the base, and the material of the dielectric layer includes silicon oxide, silicon nitride, or silicon oxynitride.

9. The bidirectional switch according to any one of claims 1 to 8, characterized in that, The bidirectional switch is a nitrogen-based bidirectional switch, the active layer is a nitrogen-based active layer, and the barrier layer is a nitrogen-based barrier layer.

10. The bidirectional switch according to any one of claims 2 to 9, characterized in that, The distance between two adjacent bases in the base is greater than or equal to 0.1 micrometers and less than or equal to 10 micrometers.

11. A method for preparing a bidirectional switch, characterized in that, include: An active layer is formed on the substrate; A barrier layer is formed on the active layer; A first gate, a second gate, a first source, a second source, and a base are formed on the first surface of the barrier layer. The first gate is disposed between the first source and the second gate, the second gate is disposed between the first gate and the second source, and the base is disposed between the first gate and the second gate. The projection of the base onto a first plane at least partially overlaps with the projection of the metal field plate structure onto the first plane. The first plane is the plane on which the first surface is located. At least one metal field plate structure is formed on the barrier layer. Each metal field plate structure in the at least one metal field plate structure includes a first field plate and a second field plate. One end of the first field plate is electrically connected to the first source electrode, and one end of the second field plate is electrically connected to the second source electrode.

12. The method according to claim 11, characterized in that, The first gate and the second gate are junction gates, each junction gate including a gate electrode and a semiconductor structure. The formation of the first gate, the second gate, the first source, the second source, and the base on the first surface of the barrier layer includes: A semiconductor layer is formed on the barrier layer; The semiconductor layer is patterned to form a semiconductor structure for the first gate, a semiconductor structure for the second gate, and the substrate. The material of the semiconductor layer includes junction-doped gallium nitride, and the doping material includes magnesium, zinc, beryllium, cadmium, or calcium.

13. The method according to claim 11, characterized in that, The formation of a first gate, a second gate, a first source, a second source, and a base on the first surface of the barrier layer includes: The first gate, the second gate, the first source, and the second source are formed on the barrier layer; A dielectric layer is formed on the barrier layer; The dielectric layer is patterned to form the substrate, and the material of the dielectric layer includes silicon oxide, silicon nitride, or silicon oxynitride.

14. An electronic device, characterized in that, It includes a drive circuit, a filter circuit, a control circuit, a power conversion circuit, and at least one bidirectional switch as described in any one of claims 1 to 10.

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