A novel RC-IGBT structure for improving switching performance

Abstract

The application provides a novel RC-IGBT structure for improving switching performance, and relates to the technical field of power semiconductor devices, and comprises a cell conduction control module, a hole injection module and a back surface electron regulation module. The cell conduction control module performs groove gate driving processing on an input gate control signal to form a conduction channel. The hole injection module performs hole injection processing on the conduction channel to form a conductance modulation state, and the hole injection processing comprises injecting hole carriers from the p+ collector region into the n-drift region. The novel RC-IGBT structure for improving switching performance improves the switching performance by adopting a groove gate structure, a hole injection module and a back surface electron regulation module and other innovative modules through the design of the novel RC-IGBT structure. By reasonably configuring the modules, the resistance during conduction is reduced, and the conduction and turn-off characteristics of the power switch are optimized by adjusting the conductance through hole injection.

Description

Technical Field

[0001] This invention relates to the field of power semiconductor device technology, specifically to a novel RC-IGBT structure for improving switching performance. Background Technology

[0002] RC-IGBTs, as power devices integrating IGBTs and freewheeling diodes (FWDs) onto a single chip, simplify PCB layout, reduce parasitic inductance and resistance, and offer fast reverse recovery and high temperature stability, thus gaining widespread use. In traditional RC-IGBT chip structures, the cell region employs a hybrid diode and IGBT structure. Electrons are injected through the front-side MOS gate channel, and holes are injected into the back-side P+ collector region to achieve conductivity modulation, resulting in a low on-state voltage drop during high-current conduction. The termination region primarily provides withstand voltage capability; the front side typically uses a multi-layer field-limiting ring structure and an insulating layer to suppress current flow. During conduction, a large number of non-equilibrium carriers are generated inside the device. During turn-off, holes are drained through the front-side emitter metal, and electrons are drained through the back-side metal layer. Based on these principles, traditional devices maintain stable output over a wide operating range and have gradually matured in industrial control and high-reliability power equipment, leading to relatively complete manufacturing processes and doping control strategies.

[0003] During the turn-off process of a traditional RC-IGBT, the P+ collector region on the back side hinders the discharge of non-equilibrium electrons to the metal electrode, creating a bottleneck and slowing down the device's turn-off speed. As carrier accumulation increases, a tail current forms in the turn-off region, significantly increasing overall turn-off losses. This phenomenon is particularly pronounced under high-voltage and high-current operating conditions, hindering the rapid extraction of carriers from the edge regions and further exacerbating the current tail extension problem. Especially as system design trends move towards higher switching frequencies, this defect significantly impacts efficiency and thermal management margins, leading to additional safety margin requirements in the driver and packaging. Consequently, traditional structures struggle to meet practical application goals in high-performance scenarios. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a novel RC-IGBT structure that improves switching performance. The technical problem this invention aims to solve is how to address the issues of electron discharge bottleneck, tail current, and increased turn-off losses in traditional RC-IGBTs during turn-off by introducing a back-side electronic adjustment module and an end-characteristic coordination module.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a novel RC-IGBT structure for improving switching performance, comprising:

[0006] A cell region is provided with an emitter electrode metal at its top. An insulating layer covers the emitter electrode metal. A trench gate structure with equal spacing along the lateral direction is fixedly connected below the insulating layer. The trench gate structure consists of a gate polysilicon, a silicon oxide gate oxide layer, and a trench from the inside to the outside. The trench gate structure is distributed in a P-base region. A P+ contact region and an N+ emitter region are provided between adjacent trenches. An n-drift region is formed below the P-base region. An FS layer is fixedly connected below the n-drift region. An n+ diode cathode region and a p+ collector region are arranged from left to right below the FS layer. A collector electrode metal is fixedly connected below the n+ diode cathode region and the p+ collector region.

[0007] The terminal area has an insulating layer at its top. Field limiting rings are fixedly connected below the insulating layer and are arranged at equal intervals in the lateral direction. The field limiting rings are distributed in the n-drift region. An FS layer is fixedly connected below the n-drift region. An n+ adjustment region and a p+ adjustment region are arranged in the lateral direction from left to right below the FS layer. The collector electrode metal is fixedly connected below the n+ adjustment region and the p+ adjustment region. A mask is covered below the collector electrode metal.

[0008] A power composite unit, the power composite unit comprising a diode section and an IGBT section;

[0009] A cell conduction control module, wherein the cell conduction control module performs trench gate drive processing on the input gate control signal to form a conduction channel;

[0010] A hole injection module performs hole injection processing on the conduction channel to form a conductivity modulation state. The hole injection processing includes injecting hole carriers from the p+ collector region to the n- drift region.

[0011] A freewheeling diode module, wherein the freewheeling diode module performs a bypass conduction process to form a freewheeling path for reverse current;

[0012] The rear electronic adjustment module discharges internal unbalanced electrons during the turn-off process to form a low-resistance electronic path.

[0013] An end-characteristic coordination module is used to coordinate and regulate the conductivity modulation state, the freewheeling path, and the low-resistance electronic path to form a compromise operating state.

[0014] Preferably, the diode portion includes the P+ contact region, the P-base region, the n-drift region, the FS layer, and the n+ diode cathode region, and the IGBT portion includes the n-drift region, the P-base region, the silicon oxide gate oxide layer, the gate structure, the gate polysilicon, the P+ contact region, the N+ emitter region, the FS layer, and the p+ collector region.

[0015] Preferably, the trench gate driving process includes applying a potential to the silicon oxide gate oxide layer using the gate polysilicon to form a controllable conduction layer, and adjusting the carrier density in the P-base region to form a low channel resistance.

[0016] Preferably, the hole injection process includes concentration establishment processing of the hole density in the n-drift region to form a conductivity modulation region.

[0017] Preferably, the back-side electronic regulation module includes the n+ regulation regions spaced laterally. The n+ regulation regions construct a low-resistance electron flow path during the turn-off period. The low-resistance electron flow path guides electron discharge through the electrical connection between the n+ regulation regions and the collector electrode metal, thereby suppressing carrier retention inside the n-drift region.

[0018] Preferably, the end-characteristic coordination module includes the n+ adjustment region and the p+ adjustment region arranged in an interlocking manner. The p+ adjustment region suppresses excessive electron injection during the conduction phase, and the n+ adjustment region enhances electron discharge during the turn-off phase.

[0019] Preferably, the coordinated control process includes the n+ adjustment region extracting internal electrons during the high current shutdown phase, and the p+ adjustment region restricting the electron flow path in the initial conduction phase and forming a hole injection region during the conduction phase.

[0020] Preferably, the carrier gradients of the n+ adjustment region and the p+ adjustment region are adaptively switched in different operating modes.

[0021] This invention provides a novel RC-IGBT structure for improving switching performance. It offers the following advantages:

[0022] This novel RC-IGBT structure, designed to improve switching performance, incorporates several innovative modules, including a trench gate structure, a hole injection module, and a rear-side electronic regulation module, thereby enhancing switching performance. By rationally configuring these modules, the resistance during conduction is reduced, and the conductance is adjusted through hole injection, thus optimizing the power switch's turn-on and turn-off characteristics.

[0023] The hole injection module and rear-side electronic regulation module employed discharge internal unbalanced electrons during turn-off, reducing carrier retention and suppressing the impact of reverse current during switching, thereby improving the stability and efficiency of the equipment. The end-characteristic coordination module optimizes conductance regulation and electron discharge processes by coordinating the operating states of each module, enhancing overall performance. Attached Figure Description

[0024] Figure 1 This is a flowchart of the core workflow of the present invention;

[0025] Figure 2 This is a schematic cross-sectional view of the RC-IGBT basic structure for improving turn-off performance according to the present invention;

[0026] Figure 3 This is a schematic cross-sectional view of the RC-IGBT structure with partitioned optimization adjustment according to the present invention;

[0027] Figure 4 This is a schematic cross-sectional view of the RC-IGBT structure that emphasizes turn-off performance in this invention;

[0028] Figure 5 This is a schematic diagram of the back-side thinning and injection process of the present invention;

[0029] Figure 6 This is a schematic diagram of the first local ion implantation on the back side of the present invention;

[0030] Figure 7 This is a schematic diagram of the second local ion implantation on the back side of the present invention;

[0031] Figure 8 This is a schematic diagram of the final structure formed on the back side of the present invention.

[0032] Among them, 101, n-drift region; 102, P-base region; 103, silicon oxide gate oxide layer; 104, trench; 105, gate polysilicon; 106, P+ contact region; 107, N+ emitter region; 108, insulating layer; 109, emitter electrode metal; 110, field limiting ring; 111, FS layer; 112, n+ diode cathode region; 113, p+ collector region; 114, collector electrode metal; 115, n+ adjustment region; 116, p+ adjustment region; 117, mask; 121, diode section; 122, IGBT section; 123, termination region. Detailed Implementation

[0033] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0034] Example 1

[0035] like Figure 1-8 As shown, this embodiment of the invention provides a novel RC-IGBT structure for improving switching performance, including a cell region. An emitter electrode metal 109 is disposed at the top of the cell region. An insulating layer 108 covers the emitter electrode metal 109. A trench gate structure, arranged at equal intervals along the lateral direction, is fixedly connected below the insulating layer 108. The trench gate structure, from the inside out, consists of a gate polysilicon 105, a silicon oxide gate oxide layer 103, and a trench 104. The trench gate structure is distributed in a P-base region 102. A P+ contact region 106 and an N+ emitter region 107 are disposed between adjacent trenches in the trench gate structure. An n-drift region 101 is formed below the P-base region 102. An FS layer 111 is fixedly connected below the n-drift region 101. An n+ diode cathode region 112 and a p+ collector region 113 are arranged from left to right below the FS layer 111. A collector electrode metal 114 is fixedly connected below the n+ diode cathode region 112 and the p+ collector region 113.

[0036] Terminal region 123, with an insulating layer 108 at the top. Field limiting rings 110 are fixedly connected below the insulating layer 108 and arranged at equal intervals in the lateral direction. The field limiting rings 110 are distributed in the n-drift region 101. FS layer 111 is fixedly connected below the n-drift region 101. n+ adjustment region 115 and p+ adjustment region 116 are arranged in the lateral direction from left to right below the FS layer 111. Collector electrode metal 114 is fixedly connected below the n+ adjustment region 115 and p+ adjustment region 116. Mask 117 covers the collector electrode metal 114.

[0037] The power composite unit includes a diode section 121 and an IGBT section 122. The diode section 121 includes a P+ contact region 106, a P-base region 102, an n-drift region 101, an FS layer 111, and an n+ diode cathode region 112. The IGBT section 122 includes an n-drift region 101, a P-base region 102, a silicon oxide gate oxide layer 103, a trench 104, a gate polysilicon 105, a P+ contact region 106, an N+ emitter region 107, an FS layer 111, and a p+ collector region 113.

[0038] The cell conduction control module performs trench gate drive processing on the input gate control signal to form a conduction channel. The trench gate drive processing includes applying a potential to the silicon oxide gate oxide layer 103 using gate polysilicon 105 to form a controllable conduction layer, and adjusting the carrier density in the P-base region 102 to form a low channel resistance.

[0039] The hole injection module performs hole injection processing on the conduction channel to form a conductivity modulation state. The hole injection processing includes injecting hole carriers from the p+ collector region 113 into the n- drift region 101. The hole injection processing also includes concentration establishment processing of the hole density in the n- drift region 101 to form a conductivity modulation region.

[0040] The freewheeling diode module bypasses the reverse current to form a freewheeling path.

[0041] The back-side electronic regulation module discharges internal non-equilibrium electrons during the turn-off process, forming a low-resistance electron pathway. The back-side electronic regulation module includes laterally spaced n+ regulation regions 115. During turn-off, the n+ regulation regions 115 construct a low-resistance electron flow path. This low-resistance electron flow path is guided by the electrical connection between the n+ regulation regions 115 and the collector electrode metal 114, thus suppressing carrier retention within the n-drift region 101.

[0042] The end-characteristic coordination module coordinates and regulates the conductance modulation state, freewheeling path, and low-resistance electron path to form a compromise operating state. The end-characteristic coordination module includes interleaved n+ regulation regions 115 and p+ regulation regions 116 in a nested manner. During the conduction phase, the interleaved n+ and p+ regulation regions 115 suppress excessive electron injection into the n+ regulation region 115, while simultaneously accelerating the opening of the p+ regulation region 116 to inject holes into the n-drift region 101, thereby reducing the voltage foldback phenomenon of the RC-IGBT during conduction. The coordinated regulation process includes the n+ regulation region 115 extracting internal electrons during the high-current turn-off phase, and the p+ regulation region 116 restricting the electron flow path in the initial conduction phase and forming a hole injection region during conduction. The carrier gradients of the n+ and p+ regulation regions 115 adaptively switch under different operating modes.

[0043] The cell region conduction control module applies a potential between the gate polysilicon 105 and the silicon oxide gate oxide layer 103 to adjust the carrier density in the P-base region 102, reduce the resistance of the conduction channel, reduce power loss during the switching process, and improve the working efficiency of the RC-IGBT.

[0044] The hole injection module injects hole carriers from the p+ collector region 113 into the n- drift region 101 to form a conductivity modulation region, control the reverse current, improve the carrier distribution during switching, optimize the switching speed, and reduce switching losses.

[0045] The freewheeling diode module bypasses the reverse current path, ensuring smooth reverse current flow and preventing damage to the device from reverse current during switching. Precise control of the reverse current enhances the device's stability and reliability.

[0046] The rear electronic regulation module constructs a low-resistance electron flow path during the turn-off process through the n+ regulation region 115, which quickly discharges the non-equilibrium electrons accumulated during the turn-off period, reduces carrier retention, improves turn-off efficiency, and avoids energy loss during high-frequency switching.

[0047] The end-characteristic coordination module coordinates the flow of electrons and holes during the turn-on and turn-off processes through the n+ adjustment region 115 and the p+ adjustment region 116. By dynamically adjusting the carrier flow path, it optimizes electron injection and emission during the switching process, thereby improving the switching speed and power efficiency of the RC-IGBT and reducing heat loss.

[0048] Example 2

[0049] By optimizing the RC-IGBT structure, the device's turn-off performance is improved while reducing voltage foldback, thus balancing conduction and turn-off performance. The specific implementation method is as follows:

[0050] 1. Construction of cell regions

[0051] like Figure 2 As shown, the optimized cell region design improves the device's turn-off performance. An emitter electrode metal 109 is located at the top of the cell region, covered by an insulating layer 108. Below the insulating layer 108 is the trench gate structure, specifically including a gate polysilicon 105, a silicon oxide gate oxide layer 103, and a trench 104. By adjusting the gate voltage, precise conduction modulation is achieved, reducing the on-resistance during conduction. In the test, the resistance when the device is on was... This reduces costs by approximately 20% compared to traditional RC-IGBTs.

[0052] 2. Trench gate driving process

[0053] A controllable conduction channel is formed by applying a voltage to the gate polysilicon 105 through the gate oxide layer 103. The conductance modulation effect of the channel optimizes the carrier density in the P-base region 102 through hole injection. In this embodiment, the gate oxide layer thickness is 95 nm. Tests show that the design improves the device's response speed and reduces voltage foldback during turn-on. In the on-state, the on-voltage drop is 2.0 V, which is 12% lower than that of a conventional RC-IGBT.

[0054] 3. Hole Injection Module

[0055] The hole injection module regulates the conductivity modulation state by injecting holes from the p+ collector region 113 into the n-drift region 101. The hole density in the n-drift region 101 is... This creates a conductivity modulation region. Through the hole injection module, the conductivity change of the device during switching is more stable, voltage fluctuations are smaller, and switching losses are reduced.

[0056] 4. Freewheeling diode module

[0057] The freewheeling diode module provides a bypass path for reverse current, ensuring that the device does not experience excessive reverse current when operating in reverse. In testing, it demonstrated a reverse current handling capability of 10A, withstanding reverse current under high power conditions, thus enhancing the device's stability.

[0058] 5. Rear electronic adjustment module

[0059] The back-side electronic regulation module forms a low-resistance electron path through the n+ regulation region 115 and the p+ regulation region 116, accelerating the discharge of non-equilibrium electrons. In this embodiment, the upper width of the n+ regulation region 115 is 5 μm and the lower width is 8 μm, while the upper width of the p+ regulation region 116 is 7 μm and the lower width is 4 μm. This design allows electrons to be discharged more quickly through the back-side collector electrode metal 114 during the turn-off phase, reducing the residence time of non-equilibrium electrons by approximately 30% and significantly improving the device's turn-off speed.

[0060] 6. End-point characteristic coordination module

[0061] To optimize the device's turn-on and turn-off performance, this embodiment employs a hybrid structure of an n+ adjustment region 115 and a p+ adjustment region 116. The n+ adjustment region 115 is narrower at the top and wider at the bottom, while the p+ adjustment region 116 is wider at the top and narrower at the bottom. In the initial stage of device turn-on, because the upper part of the n+ adjustment region 115 is narrower and the upper part of the p+ adjustment region 116 is wider, some current flows to the p+ adjustment region 116, accelerating its activation to inject holes into the n-drift region 101. This accelerates the transition of the device from unipolar carrier mode to bipolar carrier mode, thereby reducing voltage foldback. Simultaneously, during device turn-off, because the lower part of the n+ adjustment region 115 is wider and the lower part of the p+ adjustment region 116 is narrower, electron flow is guided to the n+ adjustment region 115, improving turn-off performance.

[0062] After testing, the voltage foldback phenomenon during the conduction phase of the device was suppressed, and the voltage foldback amplitude was reduced from the original 15V to 6V, thus improving the stability of the conduction performance.

[0063] 7. Manufacturing process

[0064] In this embodiment, the manufacturing process of the RC-IGBT is as follows:

[0065] Front-end structure: The front-end structure is first formed through photolithography, thin film growth, etching and ion implantation processes.

[0066] Backside processing: After grinding the back side of the wafer to the target thickness, n-type and p-type ion implantation is performed to form the n+ adjustment region 115 and the p+ adjustment region 116. After implantation, annealing is performed to ensure optimal ion diffusion.

[0067] Mask 117 and Ion Implantation: The back side uses photolithography to perform two ion implantations through mask 117, respectively achieving shallower and deeper ion implantation layers to form optimized carrier channels.

[0068] Final metallization: Finally, the collector electrode metal 114 is deposited on the back side to complete the final structure of the device.

[0069] 8. Performance Evaluation

[0070] Performance testing showed that the RC-IGBT in this embodiment exhibits excellent turn-off delay, with a turn-off time of 180ns, a 25% improvement over conventional devices. During conduction, when the current reaches 50A, the forward voltage drop is only 2.0V, resulting in improved efficiency. The non-equilibrium electron emission rate during turn-off is 30% higher than that of conventional designs, significantly accelerating the device's turn-off speed and making it suitable for high-frequency switching applications.

[0071] The RC-IGBT structure in this embodiment improves the device's turn-off performance through an optimized hybrid design of the n+ adjustment region 115 and the p+ adjustment region 116. Simultaneously, it reduces voltage foldback by optimizing the conductance modulation effect. Refined manufacturing processes ensure the device's stability and high efficiency, making it suitable for high-frequency switching and high-power applications.

[0072] Example 3

[0073] By optimizing the structure of the RC-IGBT's termination region 123, its conduction and turn-off performance are improved, reducing voltage foldback and increasing turn-off speed under high current operation. The specific implementation method is as follows:

[0074] 1. Device structure and parameter design

[0075] like Figure 3 As shown, the RC-IGBT structure design used in this embodiment is as follows:

[0076] Structural design of cell region and terminal region 123:

[0077] The portion near the cell region:

[0078] The n+ adjustment region 115 has a width of 0.5 μm and a length of 1.2 μm. It restricts electron flow during the initial conduction phase, reducing voltage foldback.

[0079] The p+ adjustment region 116 has a width of 1.0 μm and a length of 1.5 μm, which helps with hole injection during the conduction phase and reduces on-resistance.

[0080] The part far from the cell region:

[0081] The n+ adjustment region 115 has a width of 1.0 μm and a length of 2.0 μm. It provides a low-resistance path for non-equilibrium electrons during turn-off, enhancing turn-off performance.

[0082] p+ adjustment region 116 has a width of 0.7μm and a length of 1.5μm, which optimizes hole discharge during shutdown and improves shutdown efficiency.

[0083] That is, the size of the n+ adjustment region 115 near the cell region is smaller than the size of the p+ adjustment region 116, while the size of the n+ adjustment region 115 far from the cell region is larger than the size of the p+ adjustment region 116, thus compromising the device's turn-off and turn-on performance.

[0084] To balance the turn-off and turn-on performance of the RC-IGBT, the dimensions of the n+ adjustment region 115 and p+ adjustment region 116 in different areas have been optimized. The smaller size of the n+ adjustment region 115 closer to the cell helps restrict electron flow and reduce voltage foldback. The larger size of the n+ adjustment region 115 further away from the cell ensures a low-resistance path during turn-off, improving turn-off efficiency. This design achieves the best trade-off between the two performance characteristics, resulting in lower resistance and faster turn-off time during both turn-on and turn-off processes.

[0085] 2. Manufacturing process

[0086] Photolithography and thin film growth:

[0087] Trench 104 is formed on the wafer surface using photolithography. Gate polysilicon 105 and silicon oxide gate oxide layer 103 are deposited to form a control gate structure. The formation of trench 104 allows for precise adjustment of the carrier density in the P-base region 102 and n-drift region 101 using ion implantation technology.

[0088] Backside grinding and ion implantation:

[0089] The back side of the wafer is ground to a thickness of 100 μm, followed by n-type phosphorus ion implantation and p-type boron ion implantation. On the back side of the terminal region 123, the deep n+ adjustment region 115 is implanted to a depth of 2.0 μm. The shallow p+ adjustment region 116 is implanted to a depth of 0.7 μm.

[0090] Annealing treatment:

[0091] After implantation, annealing is performed at 1050℃ for 30 minutes to ensure the activity and stability of the ion implantation region.

[0092] Collector electrode metal 114 deposition:

[0093] A collector electrode metal 114 is formed on the back side using an evaporation deposition process. The collector electrode metal 114 connects the n+ adjustment region 115 and the p+ adjustment region 116, and is connected to an external circuit through metal leads.

[0094] 3. Performance Testing and Verification

[0095] To verify the effectiveness of the structure, the following performance tests were performed:

[0096] On-resistance test:

[0097] The on-resistance is obtained by measuring the current and voltage when the device is turned on. Compared to the traditional RC-IGBT structure, it reduces costs by approximately 20%.

[0098] Shutdown performance test:

[0099] During the device turn-off process, the time from turn-on to turn-off and the change in current were measured. The test results showed that the turn-off time of the device was 35ns, which was reduced by 15% compared with the traditional design, and the efficiency of non-equilibrium electron removal during the turn-off process was improved.

[0100] Voltage foldback test:

[0101] Under high current conditions, the voltage-current characteristics were measured. The results showed that as the current increased, the voltage foldback phenomenon was effectively suppressed. During the turn-off process, the voltage foldback phenomenon was reduced by about 30%.

[0102] 4. Data Analysis

[0103] Conductivity:

[0104] On-resistance: This represents a decrease of approximately 20%.

[0105] The current path through the n+ emitter region 107 to the collector electrode metal 114 reduces conduction losses.

[0106] Shutdown performance:

[0107] Shutdown time: 35ns, a reduction of 15%.

[0108] The unbalanced electron discharge path provides a low-resistance pathway through the n+ adjustment region 115, ensuring a faster turn-off speed.

[0109] Voltage foldback phenomenon:

[0110] With optimized structural design, the amplitude of voltage foldback is reduced by 30% under high current. The occurrence of voltage foldback is suppressed by the hybrid structure of n+ regulation region 115 and p+ regulation region 116.

[0111] 5. Implementation Results

[0112] This embodiment demonstrates that by introducing optimized n+ adjustment region 115 and p+ adjustment region 116 into the termination region 123 of the RC-IGBT, turn-off performance is improved and voltage foldback during turn-on is reduced. Specific data verification shows that the above solution improves the operating efficiency of the RC-IGBT device and exhibits higher stability and reliability in high-frequency switching applications.

[0113] Through optimized design and manufacturing processes in this embodiment, the turn-off and turn-on performance of the RC-IGBT are improved. The provided performance test data demonstrates that this implementation scheme has strong practical application value and is suitable for high-efficiency power conversion and switching applications.

[0114] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A novel RC-IGBT structure for improving switching performance, characterized in that, include: A cell region is provided with an emitter electrode metal (109) at its top. An insulating layer (108) covers the emitter electrode metal (109). A trench gate structure with equal spacing along the lateral direction is fixedly connected below the insulating layer (108). The trench gate structure consists of a gate polysilicon (105), a silicon oxide gate oxide layer (103), and a trench (104) from the inside out. The trench gate structure is distributed in the P-base region (102). The trench gate structure is located between adjacent trenches. A P+ contact region (106) and an N+ emitter region (107) are provided in the space between the P base region (102). An n- drift region (101) is formed below the P base region (102). An FS layer (111) is fixedly connected below the n- drift region (101). An n+ diode cathode region (112) and a p+ collector region (113) are arranged from left to right below the FS layer (111). A collector electrode metal (114) is fixedly connected below the n+ diode cathode region (112) and the p+ collector region (113). Terminal area (123), the top of the terminal area (123) is provided with an insulating layer (108), and a field limiting ring (110) is fixedly connected below the insulating layer (108) and arranged at equal intervals in the lateral direction. The field limiting ring (110) is distributed in the n-drift region (101). The FS layer (111) is fixedly connected below the n-drift region (101). The n+ adjustment region (115) and the p+ adjustment region (116) are arranged in the lateral direction from left to right below the FS layer (111). The collector electrode metal (114) is fixedly connected below the n+ adjustment region (115) and the p+ adjustment region (116). A power composite unit, the power composite unit comprising a diode section (121) and an IGBT section (122). A cell conduction control module, wherein the cell conduction control module performs trench gate drive processing on the input gate control signal to form a conduction channel; A hole injection module performs hole injection processing on the conduction channel to form a conductivity modulation state. The hole injection processing includes injecting hole carriers from the p+ collector region (113) into the n-drift region (101). A freewheeling diode module, wherein the freewheeling diode module performs a bypass conduction process to form a freewheeling path for reverse current; The rear electronic adjustment module discharges internal unbalanced electrons during the turn-off process to form a low-resistance electronic path. An end-characteristic coordination module is used to coordinate and regulate the conductivity modulation state, the freewheeling path, and the low-resistance electronic path to form a compromise operating state.

2. The novel RC-IGBT structure for improving switching performance according to claim 1, characterized in that: The diode section (121) includes the P+ contact region (106), the P-base region (102), the n-drift region (101), the FS layer (111), and the n+ diode cathode region (112). The IGBT section (122) includes the n-drift region (101), the P-base region (102), the silicon oxide gate oxide layer (103), the trench (104), the gate polysilicon (105), the P+ contact region (106), the N+ emitter region (107), the FS layer (111), and the p+ collector region (113).

3. The novel RC-IGBT structure for improving switching performance according to claim 1, characterized in that: The trench gate drive process includes applying a potential to the silicon oxide gate oxide layer (103) using the gate polysilicon (105) to form a controllable conduction layer, and adjusting the carrier density in the P-base region (102) to form a low channel resistance.

4. The novel RC-IGBT structure for improving switching performance according to claim 1, characterized in that: The hole injection process includes concentration establishment processing of the hole density in the n-drift region (101) to form a conductivity modulation region.

5. A novel RC-IGBT structure for improving switching performance according to claim 1, characterized in that: The back-side electronic regulation module includes the n+ regulation regions (115) spaced laterally. The n+ regulation regions (115) construct a low-resistance electron flow path during the turn-off period. The low-resistance electron flow path guides electron discharge through the electrical connection between the n+ regulation regions (115) and the collector electrode metal (114), thereby suppressing carrier retention inside the n-drift region (101).

6. A novel RC-IGBT structure for improving switching performance according to claim 1, characterized in that: The end-characteristic coordination module includes the n+ adjustment region (115) and the p+ adjustment region (116) arranged in an interlocking manner. The p+ adjustment region (116) suppresses excessive electron injection during the conduction phase, and the n+ adjustment region (115) enhances electron discharge during the turn-off phase.

7. A novel RC-IGBT structure for improving switching performance according to claim 6, characterized in that: The coordinated control process includes the n+ adjustment region (115) extracting internal electrons during the high current turn-off phase, and the p+ adjustment region (116) restricting the electron flow path in the initial stage of conduction and forming a hole injection region during conduction.

8. A novel RC-IGBT structure for improving switching performance according to claim 1, characterized in that: The carrier gradients of the n+ adjustment region (115) and the p+ adjustment region (116) are adaptively switched in different operating modes.

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