Bidirectional HEMT devices and electronic equipment

Abstract

This application provides a bidirectional HEMT device and an electronic device. The bidirectional HEMT device includes a substrate, a channel layer, a barrier layer, a first electrode, a second electrode, a first gate, a second gate, and an auxiliary semiconductor layer. The first electrode, second electrode, first gate, and second gate are all located on the side of the barrier layer away from the channel layer. The area covered between the first gate and the second gate is a first region, and the area covered between the first electrode and the first gate, or the area covered by the second electrode and the second gate, is a second region. The auxiliary semiconductor layer is located on the side of the barrier layer away from the substrate and is in contact with the barrier layer, covering at least a portion of the first region. In the device's on-state, the concentration of two-dimensional electron gas in the portion covered by the auxiliary semiconductor layer is higher than the concentration of two-dimensional electron gas in the second region. This improves the mutual interference between the first gate and the second gate.

Description

Technical Field

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

[0002] High electron mobility transistors (HEMTs), with their high breakdown electric field, high electron saturation velocity, and excellent high-frequency characteristics, have become the core of next-generation wide-bandgap power semiconductor devices. Traditional HEMTs are unidirectional conductors, which cannot meet the requirements of modern power electronic systems for bidirectional energy flow. Therefore, bidirectional HEMTs have emerged, which achieve controllable switching of current in both forward and reverse directions through symmetrical structural designs (such as dual-gate, dual-source, or common-drain topologies). However, in forward and reverse operating modes, mutual interference between the two gates can lead to interference with switching control sensitivity, requiring further optimization. Summary of the Invention

[0003] This application addresses the shortcomings of related technologies by proposing a bidirectional HEMT device and electronic device to solve the problem of mutual interference between the two gates in bidirectional HEMT devices.

[0004] This application provides a bidirectional HEMT device with a blocking voltage capability of at least 400V, the bidirectional HEMT device comprising: Substrate; A channel layer is located on one side of the substrate; A barrier layer is located on the side of the channel layer away from the barrier layer; The first electrode, the second electrode, the first gate, and the second gate are all located on the side of the barrier layer away from the channel layer; the first gate and the second gate are both located between the first electrode and the second electrode, with the first gate being closer to the first electrode than the second gate; the bidirectional HEMT device has a forward operating mode and a reverse operating mode. In the forward operating mode, the potential of the first electrode is lower than the potential of the second electrode, at which time the first electrode is the source and the second electrode is the drain; in the reverse operating mode, the potential of the first electrode is higher than the potential of the second electrode, at which time the first electrode is the drain and the second electrode is the source; the area covered between the first gate and the second gate is the first region, and the area covered between the first electrode and the first gate or the area covered by the second electrode and the second gate is the second region; An auxiliary semiconductor layer is located on the side of the barrier layer away from the substrate and in contact with the barrier layer. The auxiliary semiconductor layer covers at least a portion of the first region. In the device-on state, the concentration of two-dimensional electron gas in the region covered by the auxiliary semiconductor layer is higher than the concentration of two-dimensional electron gas in the second region.

[0005] This application provides an electronic device, including the aforementioned bidirectional HEMT device.

[0006] The beneficial effects of this application include: In this embodiment, since the concentration of two-dimensional electron gas in at least a portion of the first region between the first gate and the second gate is higher than that between the first electrode and the first gate / second electrode / second gate, when the potential of the first electrode is lower than that of the second electrode, the first electrode acts as the source and the second electrode as the drain. In this case, the first gate acts as the control gate. Because the concentration of two-dimensional electron gas between the first gate and the second gate is higher, when the two-dimensional electron gas below the first gate is depleted, the complete depletion of the two-dimensional electron gas between the first gate and the second gate can be avoided. That is, when the first gate control device is turned off, interference with the second gate can be avoided. Similarly, when the potential of the first electrode is higher than that of the second electrode, the first electrode acts as the drain and the second electrode as the source. In this case, the second gate acts as the control gate. Because the concentration of two-dimensional electron gas between the first gate and the second gate is higher, when the two-dimensional electron gas below the second gate is depleted, the complete depletion of the two-dimensional electron gas between the first gate and the second gate can be avoided. That is, when the first gate control device is turned off, interference with the second gate can be avoided.

[0007] Additional aspects and advantages of this application will be set forth in part in the description which follows, and will become apparent from the description or may be learned by practice of this application. Attached Figure Description

[0008] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0009] Figure 1 The diagram shown is a structural schematic of a bidirectional HEMT device in the related art; Figures 2-28 The diagram shows the structure of several bidirectional HEMT devices provided in the exemplary embodiments of this application.

[0010] In the figure: 10-substrate; 20-channel layer; 30-barrier layer; A1-first region; A11-first sub-region, A12-second sub-region; A21 / A22-second region; 30a-first sub-barrier layer; 30b-second sub-barrier layer; 301-third doped region; 302-fourth doped region; 303-first trench; 304-second trench; 31-doped region; 311-first doped region; 312-second doped region; 41-first electrode; 42-second electrode; 43- First gate; 44-Second gate; 51-First cap layer; 52-Second cap layer; 60-Auxiliary semiconductor layer; 61-First auxiliary semiconductor section; 62-Second auxiliary semiconductor section; 601-First auxiliary semiconductor layer; 602-Second auxiliary semiconductor layer; 603-Auxiliary doped region; 60a / 60b / 60c-Sub-auxiliary semiconductor layer; 70-Insertion layer; 81-First field plate; 82-Second field plate; 811-First sub-field plate segment; 812-Second sub-field plate segment; 90-Passivation layer. Detailed Implementation

[0011] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numerals in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.

[0012] The terminology used in this application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The singular forms “a,” “the,” and “the” used in this application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used herein refers to and includes any or all possible combinations of one or more of the associated listed items.

[0013] It should be understood that when describing the structure of a component, when referring to a layer or region as being "above" or "on top of" another layer or region, it can mean that it is directly above the other layer or region, or that it contains other layers or regions between it and the other layer or region. Furthermore, if the component is flipped over, that layer or region will be located "below" or "under" the other layer or region.

[0014] The semiconductor devices and their fabrication methods in the embodiments of this application will be described in detail below with reference to the accompanying drawings. Unless otherwise specified, the features in the following embodiments may complement or combine with each other.

[0015] Figure 1The diagram shows a schematic of a bidirectional HEMT device. The bidirectional HEMT device includes a first electrode 41, a second electrode 42, a first gate 43, and a second gate 44, wherein the first gate 43 is closer to the first electrode 41 than the second gate 44.

[0016] When the first electrode 41 is connected to a low potential and the second electrode 42 is connected to a high potential, the first electrode 41 acts as the source and the second electrode 42 acts as the drain. Current flows from the second electrode 42 to the first electrode 41, and electrons flow from the first electrode 41 to the second electrode 42. Since the first gate 43 is closer to the first electrode 41, the first gate 43 acts as a switch, controlling the conduction or cutoff between the first electrode 41 and the second electrode 42. When the device is in high-voltage off-state condition, that is, at a gate voltage V... GS <threshold voltage V th (For normally off devices, V) GS =0, for normally open devices, V GS In the off state (where the value is negative), it simultaneously withstands a high source-drain voltage V. DS (e.g. V) DS (400V or greater) ； The potential of the second electrode 42 is higher than that of the first electrode 41. After the 2DEG below the first gate 43 is depleted, it will continue to be consumed in the direction of higher potential (that is, consumed in the direction closer to the second electrode 42). At the same time, when a field plate is provided above the gate and the field plate covers the area between the first gate and the second gate, the field plate will also promote the depletion of the 2DEG. As a result, the 2DEG below the second gate 44 may be consumed or even depleted, which will cause parasitic parameters such as capacitive coupling between the second gate 44 and the substrate 10 to be unable to be shielded by the 2DEG. This will cause the gate voltage of the second gate 44 to fluctuate and fail to reach the preset gate voltage, thus causing it to turn off falsely.

[0017] Conversely, when the first electrode 41 is connected to a high potential and the second electrode 42 is connected to a low potential, the first electrode 41 acts as the drain and the second electrode 42 acts as the source. Current flows from the first electrode 41 to the second electrode 42, and electrons flow from the second electrode 42 to the first electrode 41. Since the second gate 44 is closer to the second electrode 42, it acts as a switch to control the conduction or cutoff between the first electrode 41 and the second electrode 42. When the device is under high-voltage turn-off conditions, because the potential of the first electrode 41 is higher than that of the second electrode 42, the 2DEG below the second gate 44 will continue to be consumed towards higher potentials (i.e., towards the first electrode 41) after it is depleted. As a result, the 2DEG below the first gate 43 may be consumed or even depleted, causing parasitic parameters such as capacitive coupling between the first gate 43 and the substrate 10 to be unable to be shielded by the 2DEG. This leads to fluctuations in the gate voltage of the first gate 43, which fails to reach the preset gate voltage, resulting in false turn-off.

[0018] This will cause control crosstalk between the first gate 43 and the second gate 44, disrupting the device's bidirectional independent switching capability.

[0019] The bidirectional HEMT device and electronic device provided in this application are intended to solve or improve the above-mentioned technical problems.

[0020] This application provides a bidirectional HEMT device with a blocking voltage capability of at least 400V, such as Figures 2-11As shown in any of the accompanying figures, the bidirectional HEMT device includes a substrate 10, a channel layer 20, a barrier layer 30, a first electrode 41, a second electrode 42, a first gate 43, a second gate 44, and an auxiliary semiconductor layer 60. The channel layer 20 is located on one side of the substrate 10; the barrier layer 30 is located on the side of the channel layer 20 away from the barrier layer 30; the first electrode 41, the second electrode 42, the first gate 43, and the second gate 44 are all located on the side of the barrier layer 30 away from the channel layer 20; the first gate 43 and the second gate 44 are both located between the first electrode 41 and the second electrode 42, with the first gate 43 being closer to the first electrode 41 than the second gate 44. The bidirectional HEMT device has a forward operating mode and a reverse operating mode. In the forward operating mode, the potential of the first electrode 41 is lower than the potential of the second electrode 42. At this time, the first electrode 41 is the source and the second electrode 42 is the drain. In the reverse working mode, the potential of the first electrode 41 is higher than that of the second electrode 42. At this time, the first electrode 41 is the drain and the second electrode 42 is the source. The area covered between the first gate 43 and the second gate 44 is the first region A1. The area covered between the first electrode 41 and the first gate 43 and the area covered by the second electrode 42 and the second gate 44 are the second regions A21 and A22, respectively. The auxiliary semiconductor layer 60 is located on the side of the barrier layer 30 away from the substrate 10 and is in contact with the barrier layer 30. The auxiliary semiconductor layer 60 covers at least a portion of the first region A1. In the device conduction state, the concentration of two-dimensional electron gas in the region covered by the auxiliary semiconductor layer 60 is higher than the concentration of two-dimensional electron gas in the second regions A21 / A22.

[0021] In this embodiment, by providing an auxiliary semiconductor layer 60, the polarization reaction can be enhanced, thereby increasing the two-dimensional electron gas concentration in the first region A1 covered by the auxiliary semiconductor layer 60. Since the two-dimensional electron gas concentration in at least a portion of the first region A1 between the first gate 43 and the second gate 44 is higher than the two-dimensional electron gas concentration between the first electrode 41 and the first gate 43 / second electrode 42 and the second gate 44, when the potential of the first electrode 41 is lower than the potential of the second electrode 42, the first electrode 41 is the source and the second electrode 42 is the drain. At this time, the first gate 43 acts as the control gate. Since the two-dimensional electron gas concentration between the first gate 43 and the second gate 44 is high, when the two-dimensional electron gas below the first gate 43 is depleted, it can prevent the two-dimensional electron gas between the first gate 43 and the second gate 44 from being completely depleted. That is, when the first gate 43 controls the device to turn off, it can prevent interference with the second gate 44. Similarly, when the potential of the first electrode 41 is higher than that of the second electrode 42, the first electrode 41 acts as the drain and the second electrode 42 acts as the source. In this case, the second gate 44 acts as the control gate. Because the concentration of the two-dimensional electron gas between the first gate 43 and the second gate 44 is high, when the two-dimensional electron gas below the second gate 44 is depleted, it can prevent the two-dimensional electron gas between the first gate 43 and the second gate 44 from being completely depleted. That is, when the first gate 43 controls the device to turn off, it can avoid interfering with the second gate 44. In summary, the bidirectional HEMT device provided in this embodiment can improve the sensitivity of device turn-on / off control under high-voltage conditions and avoid the situation where the first gate 43 and the second gate 44 interfere with each other, leading to false turn-off. In this application, the blocking voltage is the maximum voltage that the bidirectional HEMT device can withstand between the first electrode 41 and the second electrode 42. When the HEMT is turned off, it prevents current from flowing. Having a blocking voltage capability of at least 400V means that the design of this device guarantees a lower limit of blocking voltage of 400V. In this embodiment, by providing an auxiliary semiconductor layer 60, the severe interference between one gate (such as the first gate 43) and the other gate (such as the second gate 44) when the latter is turned off in a bidirectional HEMT device is avoided. This solution is particularly suitable for high-voltage devices, such as V... DS Devices with voltages of 400V, 700V, or 1200V or higher.

[0022] In some embodiments, the auxiliary semiconductor layer 60 is spaced apart from both the first gate 43 and the second gate 44 in a direction parallel to the surface of the substrate 10 toward the barrier layer 30.

[0023] In some embodiments, the first gate 43 and the second gate 44 have identical structures, and the first electrode 41 and the second electrode 42 are substantially symmetrically arranged about the central axis CC of the first gate 43 and the second gate 44. The central axis CC of the first gate 43 and the second gate 44 is perpendicular to the surface of the substrate 10 facing the channel layer 20. This ensures that the bidirectional HEMT device has the same on-resistance in both forward and reverse directions, consistent switching speed, and that the symmetrical layout results in uniform electric field, current density, and temperature distribution, improving reliability and lifespan.

[0024] In some embodiments, the first region A1 includes a first sub-region A11 and a second sub-region A12 surrounding the first sub-region A11. An auxiliary semiconductor layer is located in the first sub-region A11. There are gaps between the first sub-region A11 and both the first gate 43 and the second gate 44. The width of the first sub-region A11 is smaller than the width of the first region A1. The two-dimensional electron gas concentration in the second sub-region A12 is lower than that in the first sub-region A11. Therefore, contact between the auxiliary semiconductor layer 60 and the first gate 43 or the second gate 44 can be avoided. The auxiliary semiconductor layer 60 can simultaneously influence the electric field distribution between the first electrode 41 and the second electrode 42, which helps to improve the threshold voltage (V1) of the bidirectional HEMT device. th If this is achieved, the device can be stably shut down.

[0025] Furthermore, the first region A1 includes a first sub-region A11, which is substantially symmetrically arranged about the central axis CC of the first gate 43 and the second gate 44. Therefore, the bidirectional HEMT device has substantially the same bidirectional conduction current and bidirectional blocking voltage capabilities in both forward and reverse modes, ensuring consistent electrical performance in both modes.

[0026] In some embodiments, the 2DEG concentration in the second sub-region A12 is substantially the same as the 2DEG concentration in the second regions A21 / A22.

[0027] In some embodiments, the auxiliary semiconductor layer 60 is made of AlGaN, InAlN, n-type GaN, or undoped GaN.

[0028] In some embodiments, such as Figure 3As shown, the auxiliary semiconductor layer 60 includes a first auxiliary semiconductor portion 61 and a second auxiliary semiconductor portion 62 disposed at intervals. The distance between the first auxiliary semiconductor portion 61 and the first gate 43 and the distance between the second auxiliary semiconductor portion 62 and the second gate 44 are substantially equal. Therefore, by distributing the first auxiliary semiconductor portion 61 and the second auxiliary semiconductor portion 62 in the region between the first gate 43 and the second gate 44, near the first gate 43 and near the second gate 44, two regions with high 2DEG concentrations can be formed between the first gate 43 and the second gate 44. That is, when the first gate 43 is turned off, two barriers are formed to block the depletion of 2DEG below the second gate 44; when the second gate 44 is turned off, two barriers are formed to block the depletion of 2DEG below the first gate 43, thus effectively avoiding mutual interference between the first gate 43 and the second gate 44.

[0029] In some embodiments, the shape of the first auxiliary semiconductor section 61 is substantially the same as the shape of the second auxiliary semiconductor section 62 to achieve symmetrical arrangement, improve device reliability and extend lifespan.

[0030] In some embodiments, such as Figure 4 As shown, the auxiliary semiconductor layer 60 includes a first auxiliary semiconductor layer 601 and a second auxiliary semiconductor layer 602 sequentially stacked on the side of the barrier layer 30 away from the substrate 10. The first auxiliary semiconductor layer 601 comprises AlN, and the second auxiliary semiconductor layer 602 comprises AlGaN. Thus, AlN exhibits extremely strong spontaneous polarization and piezoelectric polarization, introducing an additional polarization step at the AlGaN / AlN interface. Multilayer stacking can accumulate a higher surface charge density, thereby enhancing the 2DEG at the underlying channel layer 20.

[0031] In some embodiments, such as Figure 5 As shown, the auxiliary semiconductor layer 60 includes multiple sub-auxiliary semiconductor layers 60a, 60b, and 60c stacked on the side of the barrier layer 30 away from the substrate 10. Along the direction from the substrate 10 to the barrier layer 30, the Al content in the sub-auxiliary semiconductor layers 60a, 60b, and 60c gradually increases. Therefore, the lower Al content molecular auxiliary semiconductor layer 60a, closer to the barrier layer 30, is more conducive to improving interface quality, alleviating the lattice mismatch stress of the high Al content AlGaN, and reducing cracks and defects. Furthermore, the higher Al content molecular auxiliary semiconductor layer 60c, farther from the barrier layer 30, is more resistant to oxidation, improving device reliability.

[0032] In some embodiments, such as Figure 6As shown, the auxiliary semiconductor layer includes an auxiliary doped region, and the ions doped in the auxiliary doped region include n-type dopants. Therefore, this embodiment can further increase the 2DEG concentration of at least a portion of the first region A1 by setting the dopant and employing ion implantation of n-type dopants, thereby avoiding mutual interference between the first gate 43 and the second gate 44.

[0033] In some embodiments, the n-type dopant includes Si or Ge.

[0034] In some embodiments, such as Figure 7 or Figure 8 As shown, the bidirectional HEMT device also includes a first field plate 81 and a second field plate 82 spaced apart. The first field plate 81 is located on the side of the first gate 43 away from the substrate 10, and the second field plate 82 is located on the side of the second gate 44 away from the substrate 10. The orthogonal projection of the first field plate 81 on the substrate 10 covers a portion of the first region A1, and the orthogonal projection of the second field plate 82 on the substrate 10 covers a portion of the first region A1.

[0035] In this embodiment, since the device is provided with a first field plate 81 and a second field plate 82, the first field plate 81 and the second field plate 82 can assist in dissipating the 2DEG below the first gate 43 or the second gate 44. Under the premise of a fixed device size, the withstand voltage of the device can be improved, that is, the device can more easily achieve high-voltage turn-off conditions. In addition, it can avoid the formation of electric field spikes that could lead to avalanche breakdown.

[0036] In some embodiments, the first field plate 81 and the second field plate 82 are symmetrically arranged about the central axis CC of the first gate 43 and the second gate 44 in the direction perpendicular to the substrate. This achieves consistent bidirectional electric field distribution adjustment.

[0037] In some embodiments, such as Figure 7 As shown, the first field plate 81 is connected to the first gate 43, and the second field plate 82 is connected to the second gate 44. In this case, both the first field plate 81 and the second field plate 82 can be gate field plates, which can maximize the suppression of electric field peaks and improve the breakdown capacitance.

[0038] In some embodiments, such as Figure 8 As shown, the first field plate 81 is connected to the first electrode 41, and the second field plate 82 is connected to the second electrode 42. In this case, both the first field plate 81 and the second field plate 82 can be source field plates, which can reduce the Miller ratio and increase the switching speed compared to the gate field plate.

[0039] In some embodiments, when the first field plate 81 is a source field plate, the orthogonal projection of the first field plate 81 onto the substrate 10 may overlap with the orthogonal projection of the first gate 43 onto the substrate 10. In other embodiments, the orthogonal projection of the first field plate 81 onto the substrate 10 may not overlap with the orthogonal projection of the first gate 43 onto the substrate 10. This can reduce the gate charge Q. g Increase switching speed.

[0040] In some embodiments, such as Figure 7 As shown, along a direction parallel to the side surface of the channel layer 20 toward the barrier layer 30, the first field plate 81 includes a plurality of sequentially connected first sub-field plate segments 811, with at least two first sub-field plate segments 811 having different spacings from the barrier layer 30. For example, Figure 7 The distances between the adjacent first subfield plate segments 811 and the barrier layer 30 shown are d1 and d2, respectively. Thus, each first subfield plate segment can adjust the electric field distribution, further reducing the probability of forming electric field peaks, which is beneficial for a uniform electric field and avoids electric field breakdown.

[0041] In some embodiments, similarly, along a direction parallel to the side surface of the channel layer 20 toward the barrier layer 30, the second field plate 82 includes a plurality of sequentially connected second sub-field plate segments 812, at least two of the second sub-field plate segments 812 having different spacings from the barrier layer 30. For example, Figure 8 The distances between the two adjacent second subfield plate segments 812 and the barrier layer 30 shown are d3 and d4, respectively. Thus, each first subfield plate segment can adjust the electric field distribution, further reducing the probability of forming electric field peaks, which is beneficial for a uniform electric field and avoids electric field breakdown.

[0042] In some embodiments, the substrate 10 may comprise silicon (Si), doped Si, silicon carbide (SiC), germanium silicide (SiGe), gallium arsenide (GaAs) or other semiconductor materials, and may also comprise sapphire, silicon-on-insulator (SOI) or other suitable materials.

[0043] In some embodiments, the channel layer 20 can be a material with high electron mobility, such as gallium nitride (GaN), aluminum nitride (AlN), gallium arsenide (GaAs), indium phosphide (InP), or indium gallium arsenide (In). x Ga 1-x As, where 0 < x < 1, aluminum gallium nitride (Al x Ga 1-x N, where 0 < x < 1, etc. Preferably, the channel layer 20 can be gallium nitride (GaN), and the bandgap of GaN is about 3.4 eV.

[0044] In some embodiments, a buffer layer (not shown) is further provided between the channel layer 20 and the substrate 10. The buffer layer is used to reduce the lattice mismatch between the substrate 10 and the channel layer 20. The material of the buffer layer may be the same as that of the channel layer 20.

[0045] In some embodiments, the barrier layer 30 may be a wide-bandgap semiconductor material, including group III-V compounds, such as aluminum gallium nitride (Al₂O₃). x Ga 1-x N, where x≤1), AlGaAs, InAlGaNi (In a Al b Ga 1-a-b N, where a+b≤1), aluminum indium phosphide (AlInP), aluminum gallium nitride (Al x Ga 1-x N, where x≤1), indium aluminum nitrogen (In x Al 1-x N, where x < 1). The bandgap width of the barrier layer 30 can be greater than the bandgap width of the channel layer 20. Preferably, the barrier layer 30 can be aluminum gallium nitride (Al₂O₃). x Ga 1- x N, where x≤1), Al x Ga 1-x The band gap of N is approximately 3.4 to 6.2 eV.

[0046] It should be noted that due to the band difference between the channel layer 20 and the barrier layer 30, the barrier layer 30 can form a potential well for electrons, which restricts the movement of electrons in the direction perpendicular to the barrier layer 30, while allowing them to move freely in the plane of the barrier layer 30. This results in the formation of a two-dimensional electron gas (2DEG) region near the surface of the channel layer 20 on the side closest to the barrier layer 30.

[0047] In some embodiments, the first electrode 41 may include a conductive material, which may include a metal, alloy, doped semiconductor material (e.g., doped crystalline silicon) or other suitable conductive material, such as Ti, Al, Ni, Cu, Au, Pt, Pd, W, TiN or other suitable materials.

[0048] In some embodiments, the second electrode 42 may include a conductive material, which may include a metal, alloy, doped semiconductor material (e.g., doped crystalline silicon) or other suitable conductive material, such as Ti, Al, Ni, Cu, Au, Pt, Pd, W, TiN or other suitable materials.

[0049] In some embodiments, the first gate 43 or the second gate 44 may include a conductive material, which may include a metal, an alloy, a doped semiconductor material (e.g., doped crystalline silicon), or other suitable conductive materials such as Ti, Al, Ni, Cu, Au, Pt, Pd, W, TiN, or other suitable materials. The drain 42 may include a conductive material, which may include a metal, an alloy, a doped semiconductor material (e.g., doped crystalline silicon), or other suitable conductive materials such as Ti, Al, Ni, Cu, Au, Pt, Pd, W, TiN, or other suitable materials.

[0050] In some embodiments, the bidirectional HEMT device further includes a passivation layer 90 located between the first gate 43 and the first field plate 81 and between the second gate 44 and the second field plate 82, for protecting the first electrode 41, the second electrode 42, the first gate 43 and the second gate 44.

[0051] In some embodiments, such as Figures 2-8 As shown in any of the accompanying figures, the bidirectional HEMT device further includes a first cap layer 51 and a second cap layer 52. The first cap layer 51 is located between the barrier layer 30 and the first gate 43, and the second cap layer 52 is located between the barrier layer 30 and the second gate 44. In this case, the bidirectional HEMT device can be a normally-off HEMT device, in which case, when no gate voltage is applied, the 2DEG below the first gate 43 and the second gate 44 is depleted. In other embodiments, the bidirectional HEMT device can also be a weakly normally-on HEMT device, in which case, when no gate voltage is applied, the 2DEG below the first gate 43 and the second gate 44 are only partially consumed.

[0052] In some embodiments, the first cap layer 51 and the second cap layer 52 can be made of p-GaN. The p-GaN in the first cap layer 51 or the second cap layer 52 can form a local pn junction with the 2DEG between the barrier layer 30 and the channel layer 20, thereby enabling the consumption of the 2DEG below the first gate 43 and the second gate 44.

[0053] When the bidirectional HEMT device includes a first cap layer 51 and a second cap layer 52, the auxiliary semiconductor layer 60 is spaced apart from both the first cap layer 51 and the second cap layer 52. In other embodiments, the auxiliary semiconductor layer 60 may also be in contact with the first cap layer 51 and / or the second cap layer 52.

[0054] In some embodiments, such as Figure 9 As shown, the bidirectional HEMT device may also be without the first cap layer 51 and the second cap layer 52. In this case, the bidirectional HEMT device may also be a normally open HEMT device.

[0055] In some embodiments, such as Figure 10As shown, the barrier layer 30 also has a first groove 303 and a second groove 304 on the side away from the channel layer 20. At least a portion of the first gate 43 is located in the first groove 303, and at least a portion of the second gate 44 is located in the second groove 304. In this embodiment, a groove structure can also be formed in the barrier layer to locally thin the barrier layer directly below the gate. When the portion of the barrier layer directly below the gate is thinned to below a certain critical thickness, the polarization charge generated in this region is significantly reduced, insufficient to induce a continuous 2DEG conductive channel at the interface. Therefore, at zero gate voltage, the channel is "cut off," thereby forming a normally-off HEMT device.

[0056] In some embodiments, such as Figure 11 As shown, the barrier layer 30 includes a third doped region 301 and a fourth doped region 302 spaced apart. The orthogonal projection of the first gate 43 on the substrate 10 overlaps with the orthogonal projection of the third doped region 301 on the substrate 10, and the orthogonal projection of the second gate 44 on the substrate 10 overlaps with the orthogonal projection of the fourth doped region 302 on the substrate 10. Both the third doped region 301 and the fourth doped region 302 contain fluoride ions. Therefore, in this embodiment, fluoride ions can be implanted into the third doped region 301 and the fourth doped region 302. On the one hand, when fluoride ions are implanted into the barrier layer 30, they capture surrounding electrons, thus becoming negatively charged fixed negative ions. On the other hand, the implanted fluoride negative ions generate a repulsive electric field opposite to the polarization electric field generated by the barrier layer 30. The reverse electric field directly cancels or neutralizes the original polarization positive charge of the barrier layer 30. Therefore, by depleting the two-dimensional electron gas, a normally-off HEMT device is formed.

[0057] Based on the same inventive concept, this application also provides an electronic device, including the bidirectional HEMT device provided in the foregoing embodiments. This electronic device can be a USB fast charger, an appliance controller, a voltage converter in an energy storage system, a battery management system, a robot joint drive device, etc.

[0058] Based on the same inventive concept, this application also provides a bidirectional HEMT device, which has a blocking voltage capability of at least 400V, such as... Figures 12-18As shown in any of the accompanying figures, the bidirectional HEMT device includes a substrate 10, a channel layer 20, a barrier layer 30, a first electrode 41, a second electrode 42, a first gate 43, and a second gate 44. The channel layer 20 is located on one side of the substrate 10; the barrier layer 30 is located on the side of the channel layer 20 away from the barrier layer 30; the first electrode 41, the second electrode 42, the first gate 43, and the second gate 44 are all located on the side of the barrier layer 30 away from the channel layer 20; the first gate 43 and the second gate 44 are both located between the first electrode 41 and the second electrode 42, with the first gate 43 being closer to the first electrode 41 than the second gate 44. The bidirectional HEMT device has a forward operating mode and a reverse operating mode. In the forward operating mode, the potential of the first electrode 41 is lower than the potential of the second electrode 42. In the first electrode 41, the first electrode 41 is the source, and in the second electrode 42, the second electrode 42 is the drain. In the reverse working mode, the potential of the first electrode 41 is higher than that of the second electrode 42, and in this mode, the first electrode 41 is the drain and the second electrode 42 is the source. The area covered between the first gate 43 and the second gate 44 is the first region A1, and the areas covered between the first electrode 41 and the first gate 43, as well as the areas covered by the second electrode 42 and the second gate 44, are the second regions A21 and A22, respectively. The barrier layer 30 includes a doped region 31, which covers at least a portion of the first region A1. The ions doped in the doped region 31 include n-type dopants. In the device on-state, the concentration of two-dimensional electron gas in the region covered by the doped region 31 is higher than the concentration of two-dimensional electron gas in the second regions A21 / A22.

[0059] In this embodiment, by doping the first region Al of the barrier layer 30 with an n-type dopant, on the one hand, the n-type dopant can activate ionization in the barrier layer 30, releasing free electrons. Under the influence of band bending and the internal electric field, these electrons will transfer to the interface between the lower-energy barrier layer and the channel layer, and fall into the triangular potential well at the interface, thereby directly increasing the total number of electrons in the channel and improving the areal density of the 2DEG. On the other hand, the doping of the AlGaN barrier layer with an n-type impurity will change the Fermi level position in this region and generate additional positive space charge. These positive charges will further enhance the built-in electric field inside the heterojunction, causing the band bending at the interface to be more severe. The deeper the band bending, the deeper and steeper the triangular potential well formed at the interface, and the more electrons it can accommodate and bind, thereby significantly increasing the concentration of the 2DEG.

[0060] Therefore, the two-dimensional electron gas concentration in the first region A1 covered by the doped region 31 can be increased. Since the two-dimensional electron gas concentration in at least part of the first region A1 between the first gate 43 and the second gate 44 is higher than that between the first electrode 41 and the first gate 43 / second electrode 42 and the second gate 44, when the potential of the first electrode 41 is lower than that of the second electrode 42, the first electrode 41 is the source and the second electrode 42 is the drain. At this time, the first gate 43 acts as the control gate. Since the two-dimensional electron gas concentration between the first gate 43 and the second gate 44 is higher, when the two-dimensional electron gas below the first gate 43 is exhausted, the two-dimensional electron gas between the first gate 43 and the second gate 44 can be prevented from being completely exhausted. That is, when the first gate 43 controls the device to turn off, interference with the second gate 44 can be avoided. Similarly, when the potential of the first electrode 41 is higher than that of the second electrode 42, the first electrode 41 acts as the drain and the second electrode 42 acts as the source. In this case, the second gate 44 acts as the control gate. Because the concentration of the two-dimensional electron gas between the first gate 43 and the second gate 44 is high, when the two-dimensional electron gas below the second gate 44 is depleted, it can prevent the two-dimensional electron gas between the first gate 43 and the second gate 44 from being completely depleted. That is, when the first gate 43 controls the device to turn off, it can avoid interfering with the second gate 44. In summary, the bidirectional HEMT device provided in this embodiment can improve the sensitivity of device turn-on / off control under high-voltage conditions and avoid the situation where the first gate 43 and the second gate 44 interfere with each other, leading to false turn-off. In this application, the blocking voltage is the maximum voltage that the bidirectional HEMT device can withstand between the first electrode 41 and the second electrode 42. When the HEMT is turned off, it prevents current from flowing. Having a blocking voltage capability of at least 400V means that the design of this device guarantees a lower limit of blocking voltage of 400V. In this embodiment, by setting the doped region 31, the severe interference between one gate (such as the first gate 43) and the other gate (such as the second gate 44) when the bidirectional HEMT device is turned off is avoided. This solution is particularly suitable for high-voltage devices, such as V DS Devices with voltages of 400V, 700V, or 1200V or higher.

[0061] In some embodiments, the doped region 31 is spaced apart from both the first gate 43 and the second gate 44.

[0062] In some embodiments, the doped regions 31 are substantially symmetrically arranged about the central axis CC of the first gate 43 and the second gate 44, and the central axis CC of the first gate 43 and the second gate 44 is perpendicular to the surface of the substrate 10 facing the channel layer 20. This ensures that the bidirectional HEMT device has the same on-resistance in both forward and reverse directions, consistent switching speed, and that the symmetrical arrangement results in uniform electric field, current density, and temperature distribution, improving reliability and lifespan.

[0063] In some embodiments, the first region A1 further includes a first sub-region A11, which is substantially symmetrically arranged about the central axis CC of the first gate 43 and the second gate 44. Thus, the bidirectional HEMT device has substantially the same bidirectional conduction current and bidirectional blocking voltage capabilities in both forward and reverse modes, ensuring consistent electrical performance in both modes.

[0064] In some embodiments, the 2DEG concentration in the second sub-region A12 is substantially the same as the 2DEG concentration in the second regions A21 / A22.

[0065] In some embodiments, such as Figure 13 As shown, the doped region 31 includes a first doped region 311 and a second doped region 312 spaced apart, with the first doped region 311 and the second doped region 312 spaced apart from both the first gate 43 and the second gate 44. Therefore, by setting the first doped region 311 and the second doped region 312 in the region between the first gate 43 and the second gate 44, respectively, two regions with high 2DEG concentrations can be formed between the first gate 43 and the second gate 44. That is, when the first gate 43 is turned off, two barriers are formed to prevent the depletion of 2DEG below the second gate 44; when the second gate 44 is turned off, two barriers are formed to prevent the depletion of 2DEG below the first gate 43, effectively avoiding mutual interference between the first gate 43 and the second gate 44.

[0066] In some embodiments, the distance between the first doped region 311 and the first gate 43 and the distance between the second doped region 312 and the second gate 44 are substantially equal. This satisfies the symmetrical arrangement, improves device reliability, and extends lifespan.

[0067] In some embodiments, the n-type dopant includes Si or Ge.

[0068] In some embodiments, in a direction perpendicular to the surface of the substrate 10 toward the channel layer 20, such as Figure 12 or Figure 13 As shown, the maximum depth of the doped region 31 is less than the maximum thickness of the barrier layer 30. This is to prevent the doped region 31 from penetrating the barrier layer 30 and turning the entire barrier layer 30 into a conductive layer, thus weakening its electrostatic control capability over the channel.

[0069] In some embodiments, such as Figure 14 or Figure 15As shown, the bidirectional HEMT device also includes a first field plate 81 and a second field plate 82 spaced apart. The first field plate 81 is located on the side of the first gate 43 away from the substrate 10, and the second field plate 82 is located on the side of the second gate 44 away from the substrate 10. The orthogonal projection of the first field plate 81 on the substrate 10 covers a portion of the first region A1, and the orthogonal projection of the second field plate 82 on the substrate 10 covers a portion of the first region A1.

[0070] Similar to the previous embodiments, in this embodiment, since the device is provided with a first field plate 81 and a second field plate 82, the first field plate 81 and the second field plate 82 can assist in dissipating the 2DEG below the first gate 43 or the second gate 44. This can improve the device's withstand voltage while maintaining a fixed device size, making it easier to achieve high-voltage turn-off operation. Furthermore, it can prevent electric field concentration from forming spikes that could lead to avalanche breakdown.

[0071] In some embodiments, the first field plate 81 and the second field plate 82 are symmetrically arranged about the central axis CC of the first gate 43 and the second gate 44 in the direction perpendicular to the substrate. This achieves consistent bidirectional electric field distribution adjustment.

[0072] In some embodiments, the orthographic projection of the first field plate 81 on the substrate 10 overlaps with the orthographic projection of the doped region 31 on the substrate 10. This allows the strong electric field at the edge of the first gate 43 to be distributed and guided to a wider surface of the doped region 31, resulting in a more uniform electric field distribution, a lower peak electric field, and a significantly improved device withstand voltage.

[0073] In some embodiments, the orthographic projection of the second field plate 82 on the substrate 10 overlaps with the orthographic projection of the doped region 31 on the substrate 10. Similarly to the aforementioned embodiments, this can achieve the distribution and guidance of the strong electric field at the edge of the second gate 44 to a wider surface of the doped region 31, resulting in a more uniform electric field distribution, a lower peak electric field, and a significantly improved device withstand voltage.

[0074] In some embodiments, such as Figure 14 As shown, the first field plate 81 is connected to the first gate 43, and the second field plate 82 is connected to the second gate 44. In this case, both the first field plate 81 and the second field plate 82 can be gate field plates, which can maximize the suppression of electric field peaks and improve the breakdown capacitance.

[0075] In some embodiments, such as Figure 15 As shown, the first field plate 81 is connected to the first electrode 41, and the second field plate 82 is connected to the second electrode 42. In this case, both the first field plate 81 and the second field plate 82 can be source field plates, which can reduce the Miller ratio and increase the switching speed compared to the gate field plate.

[0076] In some embodiments, when the first field plate 81 is a source field plate, the orthogonal projection of the first field plate 81 onto the substrate 10 may overlap with the orthogonal projection of the first gate 43 onto the substrate 10. In other embodiments, the orthogonal projection of the first field plate 81 onto the substrate 10 may not overlap with the orthogonal projection of the first gate 43 onto the substrate 10. This can reduce the gate charge Q. g Increase switching speed.

[0077] In some embodiments, such as Figure 14 As shown, along a direction parallel to the side surface of the channel layer 20 toward the barrier layer 30, the first field plate 81 includes a plurality of sequentially connected first sub-field plate segments 811, with at least two first sub-field plate segments 811 having different spacings from the barrier layer 30. For example, Figure 14 The distances between the adjacent first subfield plate segments 811 and the barrier layer 30 shown are d5 and d6, respectively. Thus, each first subfield plate segment 811 can adjust the electric field distribution, further reducing the probability of forming electric field peaks, which is beneficial for a uniform electric field and avoids electric field breakdown.

[0078] In some embodiments, similarly, along a direction parallel to the side surface of the channel layer 20 toward the barrier layer 30, the second field plate 82 includes a plurality of sequentially connected second sub-field plate segments 812, at least two of the second sub-field plate segments 812 having different spacings from the barrier layer 30. For example, Figure 14 The distances between the adjacent second subfield plate segments 812 and the barrier layer 30 shown are d7 and d8, respectively. Thus, each second subfield plate segment 812 can adjust the electric field distribution, further reducing the probability of forming electric field peaks, which is beneficial for a uniform electric field and avoids electric field breakdown.

[0079] In some embodiments, such as Figures 12-15 As shown in any of the accompanying figures, the bidirectional HEMT device further includes a first cap layer 51 and a second cap layer 52. The first cap layer 51 is located between the barrier layer 30 and the first gate 43, and the second cap layer 52 is located between the barrier layer 30 and the second gate 44. In this case, the bidirectional HEMT device can be a normally-off HEMT device, in which case, when no gate voltage is applied, the 2DEG below the first gate 43 and the second gate 44 is depleted. In other embodiments, the bidirectional HEMT device can also be a weakly normally-on HEMT device, in which case, when no gate voltage is applied, the 2DEG below the first gate 43 and the second gate 44 are only partially consumed.

[0080] In some embodiments, the first cap layer 51 and the second cap layer 52 can be made of p-GaN. The p-GaN in the first cap layer 51 or the second cap layer 52 can form a local pn junction with the 2DEG between the barrier layer 30 and the channel layer 20, thereby enabling the consumption of the 2DEG below the first gate 43 and the second gate 44.

[0081] When the bidirectional HEMT device includes a first cap layer 51 and a second cap layer 52, the doped region 31 is spaced apart from both the first cap layer 51 and the second cap layer 52. In other embodiments, the doped region 31 may also be in contact with the first cap layer 51 and / or the second cap layer 52.

[0082] In some embodiments, such as Figure 16 As shown, the bidirectional HEMT device may also be without the first cap layer 51 and the second cap layer 52. In this case, the bidirectional HEMT device may also be a normally open HEMT device.

[0083] In some embodiments, such as Figure 17 As shown, the barrier layer 30 also has a first groove 303 and a second groove 304 on the side away from the channel layer 20. At least a portion of the first gate 43 is located in the first groove 303, and at least a portion of the second gate 44 is located in the second groove 304. In this embodiment, a groove structure can also be formed in the barrier layer to locally thin the barrier layer directly below the gate. When the portion of the barrier layer directly below the gate is thinned to below a certain critical thickness, the polarization charge generated in this region is significantly reduced, insufficient to induce a continuous 2DEG conductive channel at the interface. Therefore, at zero gate voltage, the channel is "cut off," thereby forming a normally-off HEMT device.

[0084] In some embodiments, such as Figure 18 As shown, the barrier layer 30 includes a third doped region 301 and a fourth doped region 302 spaced apart. The orthogonal projection of the first gate 43 on the substrate 10 overlaps with the orthogonal projection of the third doped region 301 on the substrate 10, and the orthogonal projection of the second gate 44 on the substrate 10 overlaps with the orthogonal projection of the fourth doped region 302 on the substrate 10. Both the third doped region 301 and the fourth doped region 302 contain fluoride ions. Therefore, in this embodiment, fluoride ions can be implanted into the third doped region 301 and the fourth doped region 302. On the one hand, when fluoride ions are implanted into the barrier layer 30, they capture surrounding electrons, thus becoming negatively charged fixed negative ions. On the other hand, the implanted fluoride negative ions generate a repulsive electric field opposite to the polarization electric field generated by the barrier layer 30. The reverse electric field directly cancels or neutralizes the original polarization positive charge of the barrier layer 30. Therefore, by depleting the two-dimensional electron gas, a normally-off HEMT device is formed.

[0085] Based on the same inventive concept, this application also provides an electronic device, including the bidirectional HEMT device provided in the foregoing embodiments. This electronic device can be a USB fast charger, an appliance controller, a voltage converter in an energy storage system, a battery management system, a robot joint drive device, etc.

[0086] Based on the same inventive concept, this application also provides a bidirectional HEMT device, which has a blocking voltage capability of at least 400V, such as... Figures 19-28 As shown in any of the accompanying figures, the bidirectional HEMT device includes a substrate 10, a channel layer 20, a barrier layer 30, a first electrode 41, a second electrode 42, a first gate 43, a second gate 44, and an insertion layer 70. The channel layer 20 is located on one side of the substrate 10; the barrier layer 30 is located on the side of the channel layer 20 away from the barrier layer 30; the first electrode 41, the second electrode 42, the first gate 43, and the second gate 44 are all located on the side of the barrier layer 30 away from the channel layer 20; the first gate 43 and the second gate 44 are both located between the first electrode 41 and the second electrode 42, with the first gate 43 being closer to the first electrode 41 than the second gate 44. The bidirectional HEMT device has a forward operating mode and a reverse operating mode. In the forward operating mode, the potential of the first electrode 41 is lower than the potential of the second electrode 42. At this time, the first electrode 41 is the source and the second electrode 42 is the drain. In the reverse working mode, the potential of the first electrode 41 is higher than that of the second electrode 42. At this time, the first electrode 41 is the drain and the second electrode 42 is the source. The area covered between the first gate 43 and the second gate 44 is the first region A1. The area covered between the first electrode 41 and the first gate 43 and the area covered by the second electrode 42 and the second gate 44 are the second regions A21 and A22, respectively. The insertion layer 70 is located on the side of the channel layer 20 away from the substrate 10 and is at least partially covered by the barrier layer 30. The insertion layer 70 covers at least part of the first region A1. In the device on state, the concentration of two-dimensional electron gas in the region covered by the insertion layer 70 is higher than the concentration of two-dimensional electron gas in the second regions A21 / A22.

[0087] In this embodiment, by setting an insertion layer 70, and taking advantage of the physical properties of the insertion layer 70, such as when the spontaneous polarization intensity of the insertion layer 70 is higher than that of the barrier layer 30, polarization discontinuity is generated at the interface between the insertion layer 70 and the adjacent channel layer 20 or barrier layer 30, the total effective polarization charge increases, attracting more electrons to the channel, which can significantly improve the 2DEG concentration in the area covered by the insertion layer 70.

[0088] Therefore, the two-dimensional electron gas concentration in the first region A1 covered by the insertion layer 70 can be increased. Since the two-dimensional electron gas concentration in at least part of the first region A1 between the first gate 43 and the second gate 44 is higher than the two-dimensional electron gas concentration between the first electrode 41 and the first gate 43 / second electrode 42 and the second gate 44, when the potential of the first electrode 41 is lower than the potential of the second electrode 42, the first electrode 41 is the source and the second electrode 42 is the drain. At this time, the first gate 43 acts as the control gate. Since the two-dimensional electron gas concentration between the first gate 43 and the second gate 44 is higher, when the two-dimensional electron gas below the first gate 43 is exhausted, the two-dimensional electron gas between the first gate 43 and the second gate 44 can be prevented from being completely exhausted. That is, when the first gate 43 controls the device to turn off, interference with the second gate 44 can be avoided. Similarly, when the potential of the first electrode 41 is higher than that of the second electrode 42, the first electrode 41 acts as the drain and the second electrode 42 acts as the source. In this case, the second gate 44 acts as the control gate. Because the concentration of the two-dimensional electron gas between the first gate 43 and the second gate 44 is high, when the two-dimensional electron gas below the second gate 44 is depleted, it can prevent the two-dimensional electron gas between the first gate 43 and the second gate 44 from being completely depleted. That is, when the first gate 43 controls the device to turn off, it can avoid interfering with the second gate 44. In summary, the bidirectional HEMT device provided in this embodiment can improve the sensitivity of device turn-on / off control under high-voltage conditions and avoid the situation where the first gate 43 and the second gate 44 interfere with each other, leading to false turn-off. In this application, the blocking voltage is the maximum voltage that the bidirectional HEMT device can withstand between the first electrode 41 and the second electrode 42. When the HEMT is turned off, it prevents current from flowing. Having a blocking voltage capability of at least 400V means that the design of this device guarantees a lower limit of blocking voltage of 400V. In this embodiment, by setting an insertion layer 70, the severe interference between one gate (such as the first gate 43) and another gate (such as the second gate 44) when the latter is turned off in a bidirectional HEMT device is avoided. This solution is particularly suitable for high-voltage devices, such as V... DS Devices with voltages of 400V, 700V, or 1200V or higher.

[0089] In some embodiments, such as Figure 19 As shown, the insertion layer 70 is located between the channel layer 20 and the barrier layer 30, and the insertion layer 70 is located in at least a portion of the first region A1. In this embodiment, polarization discontinuities are generated at the interfaces between the insertion layer 70 and the channel layer 20, and between the insertion layer 70 and the barrier layer 30, which increases the total effective polarization charge, attracts more electrons to the channel, and can improve the 2DEG concentration.

[0090] In some embodiments, the material of the insertion layer 70 includes AlN, thereby introducing an additional polarization step at the interface between the barrier layer 30 and the channel layer 20 by utilizing the extremely strong spontaneous polarization and piezoelectric polarization of AlN.

[0091] In some embodiments, such as Figure 20 As shown, the barrier layer 30 includes a first sub-barrier layer 30a and a second sub-barrier layer 30b sequentially stacked on the channel layer 20. An insertion layer 70 is located between the first sub-barrier layer 30a and the second sub-barrier layer 30b, and is situated in at least a portion of the first region A1. Therefore, polarization discontinuities can be generated at the interfaces between the first sub-barrier layer 30a and the insertion layer 70, and between the second sub-barrier layer 30b and the insertion layer 70, increasing the total effective polarization charge, attracting more electrons to the channel, and also increasing the concentration of 2DEG.

[0092] In some embodiments, the material of the insert layer 70 includes AlN.

[0093] In some embodiments, the insertion layer 70 is spaced apart from both the first gate 43 and the second gate 44.

[0094] In some embodiments, the insertion layer 70 is substantially symmetrically arranged about the central axis CC of the first gate 43 and the second gate 44, and the central axis CC of the first gate 43 and the second gate 44 is perpendicular to the surface of the substrate 10 facing the channel layer 20. This ensures that the bidirectional HEMT device has the same on-resistance in both forward and reverse directions, consistent switching speed, and that the symmetrical arrangement results in uniform electric field, current density, and temperature distribution, improving reliability and lifespan.

[0095] In some embodiments, the first region A1 further includes a first sub-region A11, which is substantially symmetrically arranged about the central axis CC of the first gate 43 and the second gate 44. Thus, the bidirectional HEMT device has substantially the same bidirectional conduction current and bidirectional blocking voltage capabilities in both forward and reverse modes, ensuring consistent electrical performance in both modes.

[0096] In some embodiments, the 2DEG concentration in the second sub-region A12 is substantially the same as the 2DEG concentration in the second regions A21 / A22.

[0097] In some embodiments, such as Figure 21 As shown, the bidirectional HEMT device also includes an auxiliary semiconductor layer 60. The auxiliary semiconductor layer 60 is located on the side of the barrier layer 30 away from the substrate 10 and is in contact with the barrier layer 30. The orthographic projection of the auxiliary semiconductor layer 60 on the substrate overlaps with the orthographic projection of the insertion layer 70 on the substrate. Therefore, an auxiliary semiconductor layer can be further added above the barrier layer 30 to increase the two-dimensional electron gas concentration in the area covered by the insertion layer 70.

[0098] In some embodiments, the auxiliary semiconductor layer 60 is made of AlGaN, InAlN, n-type GaN, or undoped GaN.

[0099] In some embodiments, such as Figure 22 As shown, the auxiliary semiconductor layer 60 includes an auxiliary doped region 603, and the ions doped in the auxiliary doped region 603 include n-type dopants. The orthographic projection of the auxiliary doped region 603 on the substrate 10 overlaps with the orthographic projection of the insertion layer 70 on the substrate 10. Therefore, similar to the previous embodiment, the 2DEG concentration below the insertion layer 70 can also be increased by doping the auxiliary doped region 603 with n-type dopants without increasing the thickness of the auxiliary semiconductor layer 60.

[0100] In some embodiments, such as Figure 23 As shown, the barrier layer 30 includes a doped region 31, and the ions doped in the doped region 31 include n-type dopants. The orthographic projection of the doped region 31 on the substrate overlaps with the orthographic projection of the insertion layer 70 on the substrate, and there is a gap between the doped region 31 and the insertion layer 70. Thus, a doped region can also be formed in the part of the barrier layer 30 that is not in contact with the insertion layer 70 to increase the 2DEG concentration below the insertion layer 70.

[0101] In some embodiments, the n-type dopant includes Si or Ge.

[0102] In some embodiments, such as Figure 24 or Figure 25 As shown, the bidirectional HEMT device also includes a first field plate 81 and a second field plate 82 spaced apart. The first field plate 81 is located on the side of the first gate 43 away from the substrate 10, and the second field plate 82 is located on the side of the second gate 44 away from the substrate 10. The orthogonal projection of the first field plate 81 on the substrate 10 covers a portion of the first region A1, and the orthogonal projection of the second field plate 82 on the substrate 10 covers a portion of the first region A1.

[0103] Similar to the previous embodiments, in this embodiment, since the device is provided with a first field plate 81 and a second field plate 82, the first field plate 81 and the second field plate 82 can assist in dissipating the 2DEG below the first gate 43 or the second gate 44. This can improve the device's withstand voltage while maintaining a fixed device size, making it easier to achieve high-voltage turn-off operation. Furthermore, it can prevent electric field concentration from forming spikes that could lead to avalanche breakdown.

[0104] In some embodiments, the first field plate 81 and the second field plate 82 are symmetrically arranged about the central axis CC of the first gate 43 and the second gate 44 in the direction perpendicular to the substrate. This achieves consistent bidirectional electric field distribution adjustment.

[0105] In some embodiments, the orthographic projection of the first field plate 81 on the substrate 10 overlaps with the orthographic projection of the insertion layer 70 on the substrate 10. This allows the strong electric field at the edge of the first gate 43 to be distributed and guided to a wider surface of the insertion layer 70, resulting in a more uniform electric field distribution, a lower peak electric field, and a significantly improved device withstand voltage.

[0106] In some embodiments, the orthographic projection of the second field plate 82 on the substrate 10 overlaps with the orthographic projection of the insertion layer 70 on the substrate 10. Similarly to the aforementioned embodiments, this can achieve the distribution and guidance of the strong electric field at the edge of the second gate 44 to a wider surface of the insertion layer 70, resulting in a more uniform electric field distribution, a lower peak electric field, and a significantly improved device withstand voltage.

[0107] In some embodiments, such as Figure 24 As shown, the first field plate 81 is connected to the first gate 43, and the second field plate 82 is connected to the second gate 44. In this case, both the first field plate 81 and the second field plate 82 can be gate field plates, which can maximize the suppression of electric field peaks and improve the breakdown capacitance.

[0108] In some embodiments, such as Figure 25 As shown, the first field plate 81 is connected to the first electrode 41, and the second field plate 82 is connected to the second electrode 42. In this case, both the first field plate 81 and the second field plate 82 can be source field plates, which can reduce the Miller ratio and increase the switching speed compared to the gate field plate.

[0109] In some embodiments, when the first field plate 81 is a source field plate, the orthogonal projection of the first field plate 81 onto the substrate 10 may overlap with the orthogonal projection of the first gate 43 onto the substrate 10. In other embodiments, the orthogonal projection of the first field plate 81 onto the substrate 10 may not overlap with the orthogonal projection of the first gate 43 onto the substrate 10. This can reduce the gate charge Q. g Increase switching speed.

[0110] In some embodiments, such as Figure 24 As shown, along a direction parallel to the side surface of the channel layer 20 toward the barrier layer 30, the first field plate 81 includes a plurality of sequentially connected first sub-field plate segments 811, with at least two first sub-field plate segments 811 having different spacings from the barrier layer 30. For example, Figure 24 The distances between the two adjacent first subfield plate segments 811 and the barrier layer 30 shown are d9 and d, respectively. 10 Therefore, each of the first subfield plate segments 811 can adjust the electric field distribution, further reducing the probability of forming electric field spikes, which is beneficial to a uniform electric field and avoids electric field breakdown.

[0111] In some embodiments, similarly, along a direction parallel to the side surface of the channel layer 20 toward the barrier layer 30, the second field plate 82 includes a plurality of sequentially connected second sub-field plate segments 812, at least two of the second sub-field plate segments 812 having different spacings from the barrier layer 30. For example, Figure 24 The distances between the two adjacent second subfield plate segments 812 and the barrier layer 30 shown are d respectively. 11 d 12 Therefore, each of the second subfield plate segments 812 can adjust the electric field distribution, further reducing the probability of forming electric field spikes, which is beneficial to a uniform electric field and avoids electric field breakdown.

[0112] In some embodiments, such as Figures 19-25 As shown in any of the accompanying figures, the bidirectional HEMT device further includes a first cap layer 51 and a second cap layer 52. The first cap layer 51 is located between the barrier layer 30 and the first gate 43, and the second cap layer 52 is located between the barrier layer 30 and the second gate 44. In this case, the bidirectional HEMT device can be a normally-off HEMT device, in which case, when no gate voltage is applied, the 2DEG below the first gate 43 and the second gate 44 is depleted. In other embodiments, the bidirectional HEMT device can also be a weakly normally-on HEMT device, in which case, when no gate voltage is applied, the 2DEG below the first gate 43 and the second gate 44 are only partially consumed.

[0113] In some embodiments, the first cap layer 51 and the second cap layer 52 can be made of p-GaN. The p-GaN in the first cap layer 51 or the second cap layer 52 can form a local pn junction with the 2DEG between the barrier layer 30 and the channel layer 20, thereby enabling the consumption of the 2DEG below the first gate 43 and the second gate 44.

[0114] When the bidirectional HEMT device includes a first cap layer 51 and a second cap layer 52, the insertion layer 70 is spaced apart from both the first cap layer 51 and the second cap layer 52. In other embodiments, the insertion layer 70 may also contact the first cap layer 51 and / or the second cap layer 52.

[0115] In some embodiments, such as Figure 26 As shown, the bidirectional HEMT device may also be without the first cap layer 51 and the second cap layer 52. In this case, the bidirectional HEMT device may also be a normally open HEMT device.

[0116] In some embodiments, such as Figure 27As shown, the barrier layer 30 also has a first groove 303 and a second groove 304 on the side away from the channel layer 20. At least a portion of the first gate 43 is located in the first groove 303, and at least a portion of the second gate 44 is located in the second groove 304. In this embodiment, a groove structure can also be formed in the barrier layer to locally thin the barrier layer directly below the gate. When the portion of the barrier layer directly below the gate is thinned to below a certain critical thickness, the polarization charge generated in this region is significantly reduced, insufficient to induce a continuous 2DEG conductive channel at the interface. Therefore, at zero gate voltage, the channel is "cut off," thereby forming a normally-off HEMT device.

[0117] In some embodiments, such as Figure 28 As shown, the barrier layer 30 includes a third doped region 301 and a fourth doped region 302 spaced apart. The orthogonal projection of the first gate 43 on the substrate 10 overlaps with the orthogonal projection of the third doped region 301 on the substrate 10, and the orthogonal projection of the second gate 44 on the substrate 10 overlaps with the orthogonal projection of the fourth doped region 302 on the substrate 10. Both the third doped region 301 and the fourth doped region 302 contain fluoride ions. Therefore, in this embodiment, fluoride ions can be implanted into the third doped region 301 and the fourth doped region 302. On the one hand, when fluoride ions are implanted into the barrier layer 30, they capture surrounding electrons, thus becoming negatively charged fixed negative ions. On the other hand, the implanted fluoride negative ions generate a repulsive electric field opposite to the polarization electric field generated by the barrier layer 30. The reverse electric field directly cancels or neutralizes the original polarization positive charge of the barrier layer 30. Therefore, by depleting the two-dimensional electron gas, a normally-off HEMT device is formed.

[0118] Based on the same inventive concept, this application also provides an electronic device, including the bidirectional HEMT device provided in the foregoing embodiments. This electronic device can be a USB fast charger, an appliance controller, a voltage converter in an energy storage system, a battery management system, a robot joint drive device, etc.

[0119] It should be noted that the dimensions of layers and regions may be exaggerated in the accompanying drawings for clarity. Furthermore, it is understood that when an element or layer is referred to as being "on" another element or layer, it can be directly on the other element, or there may be intermediate layers. Additionally, it is understood that when an element or layer is referred to as being "below" another element or layer, it can be directly below the other element, or there may be more than one intermediate layer or element. Furthermore, it is also understood that when a layer or element is referred to as being "between" two layers or two elements, it can be the only layer between the two layers or two elements, or there may be more than one intermediate layer or element. Similar reference numerals throughout indicate similar elements.

[0120] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0121] Other embodiments of this application will readily occur to those skilled in the art upon consideration of the specification and practice of the disclosure herein. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this application are indicated by the claims.

[0122] It should be understood that this application is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this application is limited only by the appended claims.

Claims

1. A bidirectional HEMT device, characterized in that, Having a blocking voltage capability of at least 400V, the bidirectional HEMT device includes: Substrate; A channel layer is located on one side of the substrate; A barrier layer is located on the side of the channel layer away from the barrier layer; The first electrode, the second electrode, the first gate, and the second gate are all located on the side of the barrier layer away from the channel layer; the first gate and the second gate are both located between the first electrode and the second electrode, with the first gate being closer to the first electrode than the second gate; the bidirectional HEMT device has a forward operating mode and a reverse operating mode. In the forward operating mode, the potential of the first electrode is lower than the potential of the second electrode, at which time the first electrode is the source and the second electrode is the drain; in the reverse operating mode, the potential of the first electrode is higher than the potential of the second electrode, at which time the first electrode is the drain and the second electrode is the source; the area covered between the first gate and the second gate is the first region, and the area covered between the first electrode and the first gate or the area covered by the second electrode and the second gate is the second region; An auxiliary semiconductor layer is located on the side of the barrier layer away from the substrate and in contact with the barrier layer. The auxiliary semiconductor layer covers at least a portion of the first region. In the device-on state, the concentration of two-dimensional electron gas in the region covered by the auxiliary semiconductor layer is higher than the concentration of two-dimensional electron gas in the second region.

2. The bidirectional HEMT device according to claim 1, characterized in that, In a direction parallel to the surface of the substrate toward the barrier layer, the auxiliary semiconductor layer is spaced apart from both the first gate and the second gate.

3. The bidirectional HEMT device according to claim 2, characterized in that, The first region includes a first sub-region and a second sub-region surrounding the first sub-region. The auxiliary semiconductor layer is located in the first sub-region. There is a gap between the first sub-region and the first gate and the second gate. The width of the first sub-region is smaller than the width of the first region. The two-dimensional electron gas concentration of the second sub-region is lower than the two-dimensional electron gas concentration of the first sub-region.

4. The bidirectional HEMT device according to claim 3, characterized in that, The first sub-region is symmetrically arranged about the central axis of the first gate and the second gate in a direction perpendicular to the substrate.

5. The bidirectional HEMT device according to claim 1, characterized in that, The auxiliary semiconductor layer is made of AlGaN, InAlN, n-type GaN, or undoped GaN.

6. The bidirectional HEMT device according to claim 1, characterized in that, The auxiliary semiconductor layer includes a first auxiliary semiconductor portion and a second auxiliary semiconductor portion disposed at intervals, wherein the distance between the first auxiliary semiconductor portion and the first gate and the distance between the second auxiliary semiconductor portion and the second gate are substantially equal.

7. The bidirectional HEMT device according to claim 1, characterized in that, The auxiliary semiconductor layer includes a first auxiliary semiconductor layer and a second auxiliary semiconductor layer sequentially stacked on the side of the barrier layer away from the substrate. The first auxiliary semiconductor layer includes AlN, and the second auxiliary semiconductor layer includes AlGaN.

8. The bidirectional HEMT device according to claim 1, characterized in that, The auxiliary semiconductor layer includes multiple sub-auxiliary semiconductor layers stacked on the side of the barrier layer away from the substrate, and the content of Al component in the sub-auxiliary semiconductor layers gradually increases along the direction from the substrate to the barrier layer.

9. The bidirectional HEMT device according to claim 1, characterized in that, The auxiliary semiconductor layer includes an auxiliary doped region, and the ions doped in the auxiliary doped region include n-type dopants.

10. The bidirectional HEMT device according to claim 9, characterized in that, The n-type dopant includes Si or Ge.

11. The bidirectional HEMT device according to claim 1, characterized in that, The bidirectional HEMT device further includes a first field plate and a second field plate spaced apart. The first field plate is located on the side of the first gate away from the substrate, and the second field plate is located on the side of the second gate away from the substrate. The orthographic projection of the first field plate on the substrate covers a portion of the first region, and the orthographic projection of the second field plate on the substrate covers a portion of the first region.

12. The bidirectional HEMT device according to claim 11, characterized in that, The first field plate and the second field plate are symmetrically arranged about the central axis of the first gate and the second gate in a direction perpendicular to the substrate.

13. The bidirectional HEMT device according to claim 11, characterized in that, The first field plate is connected to the first gate, and the second field plate is connected to the second gate.

14. The bidirectional HEMT device according to claim 11, characterized in that, The first field plate is connected to the first electrode, and the second field plate is connected to the second electrode.

15. The bidirectional HEMT device according to claim 11, characterized in that, Along a direction parallel to the side surface of the channel layer toward the barrier layer, the first field plate includes a plurality of sequentially connected first sub-field plate segments, and at least two of the first sub-field plate segments have different spacings from the barrier layer; And / or, along a direction parallel to one side surface of the channel layer toward the barrier layer, the second field plate includes a plurality of sequentially connected second sub-field plate segments, at least two of the second sub-field plate segments having different spacings from the barrier layer.

16. The bidirectional HEMT device according to claim 1, characterized in that, The bidirectional HEMT device further includes a first cap layer and a second cap layer, wherein the first cap layer is located between the barrier layer and the first gate, and the second cap layer is located between the barrier layer and the second gate.

17. The bidirectional HEMT device according to claim 1, characterized in that, The barrier layer is further provided with a first groove and a second groove on the side away from the channel layer, at least a portion of the first gate is located in the first groove, and at least a portion of the second gate is located in the second groove.

18. The bidirectional HEMT device according to claim 1, characterized in that, The barrier layer includes a third doped region and a fourth doped region spaced apart. The orthographic projection of the first gate on the substrate overlaps with the orthographic projection of the third doped region on the substrate. The orthographic projection of the second gate on the substrate overlaps with the orthographic projection of the fourth doped region on the substrate. Both the third doped region and the fourth doped region include fluoride ions.

19. An electronic device, characterized in that, Includes the bidirectional HEMT device as described in any one of claims 1 to 18.

Images