Reverse conducting IGBT device and backside manufacturing method
By employing laser annealing to form oxygen-doped and alternating doped regions during the back-side fabrication process of reverse-conducting IGBT devices, the bounce problem of reverse-conducting IGBT devices was solved, improving wafer yield and device reliability.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- GTA SEMICON CO LTD
- Filing Date
- 2026-05-18
- Publication Date
- 2026-07-14
Smart Images
Figure CN122395974A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the technical field of semiconductor fabrication methods, and more specifically, to a reverse-conducting IGBT device and a method for manufacturing its back side. Background Technology
[0002] The reverse-conducting insulated-gate bipolar transistor (RC-IGBT) integrates a traditional IGBT and a freewheeling diode onto a single chip, achieving dual functions of controllable switching and reverse freewheeling. Compared to discrete solutions, the RC-IGBT significantly improves power density, reduces parasitic parameters, and optimizes thermal management, demonstrating clear and significant application prospects in high-efficiency energy conversion. Furthermore, it effectively complements wide-bandgap semiconductor technology, driving converters towards greater compactness and reliability.
[0003] However, reverse-conducting IGBTs often face a snapback problem in practical applications, i.e., a snapback phenomenon in the forward conduction characteristics, leading to increased on-state losses and limited current output capability. Existing solutions mainly focus on the design end, optimizing the layout of the local N-type region on the back side and optimizing the doping distribution of the buffer layer. For example, designing the IGBT leader region or adjusting the patterned distribution of the P-type / N-type regions, and using a relatively shallow buffer layer, can suppress the snapback problem. However, the above designs can easily have an adverse impact on wafer yield, especially in the processing of large-size thin wafers, where the uniformity control of the back side implantation and annealing processes is difficult, easily leading to local defects or abnormal doping distribution, further reducing yield.
[0004] Therefore, how to effectively suppress the bounce problem in reverse-conducting IGBT devices while improving wafer manufacturing yield has become a technical challenge that urgently needs to be solved in this field.
[0005] It should be noted that the information disclosed in the background section above is only used to enhance the understanding of the background of the present invention, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention
[0006] To address the problems in the prior art, the present invention aims to provide a reverse-conducting IGBT device and a back-side fabrication method. This fabrication method can alleviate the snapback problem that easily occurs when the reverse-conducting IGBT is forward-conducting, thereby improving wafer yield.
[0007] A first aspect of the present invention provides a method for manufacturing the back side of a reverse-conducting IGBT device, comprising the following steps: An N-type substrate is provided, the front side of which has the front structure of an IGBT device; The back side of the substrate is annealed in an oxygen-containing atmosphere using a laser annealing process to form an oxygen-doped region on the back side of the substrate. Within the oxygen-doped region, N-type doped regions and P-type doped regions are formed respectively, with the N-type doped regions and the P-type doped regions being distributed alternately side by side. A hydrogen ion buffer layer is formed on the back side of the substrate; A back metal layer is formed on the back side of the substrate.
[0008] According to a first aspect of the invention, the oxygen-containing atmosphere is a pure oxygen atmosphere or a mixture of oxygen and an inert gas.
[0009] According to a first aspect of the invention, the oxygen volume fraction in the oxygen-containing atmosphere is greater than 20%.
[0010] According to a first aspect of the invention, the energy of the laser annealing process is 2.0J~2.6J.
[0011] According to a first aspect of the invention, the depth of the oxygen-doped region is 1 μm to 2 μm; and / or
[0012] The oxygen atom concentration in the oxygen-doped region is greater than 1 × 10⁻⁶. 16 atoms / cm 3 .
[0013] According to a first aspect of the invention, in the step of forming a hydrogen ion buffer layer on the back side of the substrate, a hydrogen ion implantation process is employed, and the peak depth of the hydrogen ion implantation is 8 μm to 12 μm; and / or
[0014] The depth of the hydrogen ion buffer layer is 3μm~30μm.
[0015] According to a first aspect of the invention, in the step of forming an N-type doped region on the back side of the substrate, the doping element is at least one of phosphorus and arsenic.
[0016] According to a first aspect of the invention, in the step of forming an N-type doped region on the back side of the substrate, the doping elements are phosphorus and arsenic, and the implantation depth of the arsenic is shallower than the implantation depth of the phosphorus.
[0017] A second aspect of the present invention provides a reverse-conducting IGBT device, fabricated using the method described in the first aspect, the reverse-conducting IGBT device comprising: An N-type substrate, the front side of which has the front structure of an IGBT device; Oxygen-doped region located on the back side of the substrate; The N-type doped region and the P-type doped region are located within the oxygen doped region, and the N-type doped region and the P-type doped region are arranged alternately side by side; A hydrogen ion buffer layer located on the back side of the substrate; and A back metal layer located on the back side of the substrate.
[0018] According to a second aspect of the invention, the depth of the oxygen-doped region is 1 μm to 2 μm; and / or
[0019] The oxygen atom concentration in the oxygen-doped region is greater than 1 × 10⁻⁶. 16 atoms / cm 3 ; and / or
[0020] The peak implantation depth of the hydrogen ions is 8 μm to 12 μm; and / or
[0021] The depth of the hydrogen ion buffer layer is 3μm~30μm.
[0022] The back-side fabrication method of the reverse-conducting IGBT device of the present invention increases the hydrogen atom adsorption carrier by performing a laser annealing process on the back side of the substrate under an oxygen-containing atmosphere, thereby obtaining an oxygen-doped region on the surface of the back side of the substrate. The oxygen atoms in the oxygen-doped region increase the hydrogen atom adsorption carrier, thereby increasing the N-type doping concentration, alleviating the snapback problem that easily occurs in the forward conduction of the reverse-conducting IGBT device and improving the wafer yield. Attached Figure Description
[0023] 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. Other features, objects, and advantages of the invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings. It is obvious that the drawings described below are merely some embodiments of the invention, and those skilled in the art can obtain other drawings based on these drawings without inventive effort. Furthermore, the drawings are merely illustrative diagrams of this disclosure and are not necessarily drawn to scale. The same reference numerals in the drawings denote the same or similar parts, and therefore repeated descriptions of them will be omitted. Some block diagrams shown in the drawings are functional entities and do not necessarily correspond to physically or logically independent entities.
[0024] Figure 1 This is a flowchart of a back-side fabrication method for a reverse-conducting IGBT device according to an embodiment of the present invention; Figures 2 to 6 This is a schematic diagram of the structure of a single crystal substrate after each step of the back-side fabrication method of a reverse-conductive IGBT device according to an embodiment of the present invention. Figure 7 A comparison of emitter and collector leakage currents between a chipset prepared by an existing method and a chipset prepared by the method of this invention. Figure 8 Output characteristic curves of a reverse-conducting IGBT device fabricated by existing methods at different gate voltages Vgs; Figure 9The output characteristic curves of a reverse-conducting IGBT device according to an embodiment of the present invention are shown at different gate voltages Vgs. Detailed Implementation
[0025] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the examples set forth herein; rather, they are provided so that this disclosure will be more comprehensive and complete, and will fully convey the concept of the exemplary embodiments to those skilled in the art. The described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.
[0026] In this specification, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics represented in connection with that embodiment or example, which are included in at least one embodiment or example of this specification. Furthermore, the specific features, structures, materials, or characteristics represented may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples represented in this specification, as well as the features of different embodiments or examples.
[0027] Throughout this specification, when it is said that a device is "connected" to another device, this includes not only "direct connection" but also "indirect connection" by placing other components in between. Terms indicating relative space, such as "front," "back," "up," and "down," are used to more easily explain the relationship of one device relative to another illustrated in the figures. These terms refer not only to their meaning in the figures but also to other meanings or operations of the device in use. For example, if the device in the figures is flipped, a device previously described as "below" another device may now be described as "above" another device. Therefore, the exemplary term "down" includes both "up" and "below." The device may be rotated 90° or other angles, and the terms representing relative space are interpreted accordingly.
[0028] Although the terms first, second, etc., are used in some instances herein to refer to various elements, these elements should not be limited by these terms. These terms are used only to distinguish one element from another. For example, first interface and second interface, etc., are used. Furthermore, as used herein, the singular forms “a,” “an,” and “the” are intended to also include the plural forms unless the context indicates otherwise. It should be further understood that the terms “comprising,” “including,” indicate the presence of the stated feature, step, operation, element, component, item, kind, and / or group, but do not exclude the presence, occurrence, or addition of one or more other features, steps, operations, elements, components, items, kinds, and / or groups. The terms “or” and “and / or” as used herein are interpreted as inclusive, or mean any one or any combination thereof. Thus, “A, B, or C” or “A, B, and / or C” means “any one of the following: A; B; C; A and B; A and C; B and C; A, B, and C.” Exceptions to this definition will only occur if the combination of elements, functions, steps, or operations is inherently mutually exclusive in some way.
[0029] Although not fully defined, all terms, including technical and scientific terms used herein, shall have the same meaning as commonly understood by one of ordinary skill in the art to which this specification pertains. Terms defined in commonly used dictionaries shall be further interpreted as having a meaning consistent with the relevant technical literature and the content of this present instruction, and shall not be over-interpreted as having an ideal or overly formulaic meaning unless otherwise defined.
[0030] The structure of the reverse-conducting IGBT device and the back-side manufacturing method of the present invention will be further described below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments are not intended to limit the scope of protection of the present invention.
[0031] This invention provides a method for manufacturing the back side of a reverse-conducting IGBT device. Figure 1 This is a flowchart of a back-side fabrication method for a reverse-conducting IGBT device according to an embodiment of the present invention. The fabrication method specifically includes the following steps: Step S1: Provide an N-type substrate 1, i.e., an N-type doped semiconductor substrate, such as a single-crystal silicon substrate, etc. The front side of the substrate has the front structure of the target reverse-conducting IGBT device (not shown in the figure). This front structure can be a conventional structure of existing IGBT devices, which can be a trench gate structure IGBT device or a planar gate structure. Taking a trench gate structure as an example, the front structure can include trenches, a gate oxide layer formed in the trenches, a gate polysilicon layer, an N-type carrier storage doped region, a P-type body region, an N-type source region, an insulating layer, and a front metal layer, etc.
[0032] Step S2: The back side of substrate 1 is annealed in an oxygen-containing atmosphere using laser annealing to form an oxygen-doped region 2 on the back side of substrate 1, see... Figure 2 Of course, before step S2, the back side of substrate 1 can also be thinned using a thinning process, which will not be elaborated here.
[0033] Laser annealing is employed to anneal the back side of the substrate in an oxygen-containing atmosphere. The high energy density of laser annealing rapidly heats the surface layer of the back side of the substrate to a molten state. Simultaneously, oxygen atoms in the atmosphere, aided by the high diffusion coefficient and solubility of molten silicon, enter the silicon lattice, forming oxygen-doped regions.
[0034] In step S2, the oxygen-containing atmosphere can be a pure oxygen atmosphere or a mixture of oxygen and an inert gas (such as argon or nitrogen). To obtain a sufficient oxygen doping concentration, it is preferable to control the volume fraction of oxygen in the oxygen-containing atmosphere to be greater than 20%, and more preferably 20% to 50%.
[0035] The laser annealing in step S2 to form an oxygen-doped region aims to achieve the following effect: in an oxygen-containing atmosphere, oxygen atoms migrate into the silicon interior under the effects of thermal diffusion and solute traction, ultimately forming an oxygen-doped region 2 with controllable depth and peak concentration.
[0036] To achieve this effect, the energy of the laser annealing process must meet the following requirements: melting or sub-melting (~1414℃) of silicon at a certain depth on the back surface of substrate 1, and promoting the reaction between the molten silicon and oxygen. Simultaneously, the energy should not be too high to avoid excessively deep molten layers, disturbance of doping distribution in the front structure, substrate warping, or slip line defects. Preferably, the energy of the laser annealing process is 2.0J to 2.6J, such as 2.2J or 2.4J. Within this energy range, a smooth melting front can be obtained, and the depth and concentration of the oxygen doping region can be stably controlled, while ensuring that back-side lattice damage can be effectively repaired in subsequent processes without affecting the device's breakdown voltage and leakage current characteristics. In one embodiment, laser annealing with an energy density of 2.4J is used in an oxygen-containing atmosphere to form a layer on the back side of the substrate with a depth of 1.5μm and an oxygen concentration of 5×10⁻⁶. 16 atoms / cm 3 Oxygen-doped regions.
[0037] In practical operation, to further precisely control the depth and concentration distribution of the oxygen-doped region 2, this can be achieved by controlling parameters such as the laser pulse width and frequency, laser scanning speed and spot size, and the number of laser annealing passes in the laser annealing process. Preferably, the depth of the oxygen-doped region 2 is 1μm~2μm, such as 1.2μm, 1.5μm, 1.8μm, etc. It should be noted that the "depth" mentioned in this article refers to the vertical distance between the side of this functional region closest to the front side of the substrate and the back surface of the substrate 1. If the depth of the oxygen-doped region 2 is too small, the oxygen-doped region is too close to the surface, and subsequent N / P implantation and metallization processes may destroy it; if the depth is too large, the oxygen-doped region will enter the drift region that mainly bears the voltage barrier, which may introduce too many recombination centers and increase forward conduction loss.
[0038] More preferably, the oxygen atom concentration in oxygen-doped region 2 is greater than 1 × 10⁻⁶. 16 atoms / cm 3 Increasing the hydrogen atom adsorbent increases the N-type doping concentration, alleviating the snapback problem that easily occurs in reverse-conducting IGBT devices during forward conduction and improving wafer yield.
[0039] After forming an oxygen-doped region 2 on the back side of substrate 1, step S3 is performed: an N-type doped region 3 and a P-type doped region 4 are formed sequentially within the oxygen-doped region 2, as shown in [reference]. Figure 3 and Figure 4 N-type doped regions 3 and P-type doped regions 4 are arranged side-by-side and alternately along the back side of substrate 1, forming a periodically arranged pattern. The N-type doped region 3 provides an electron flow path during reverse conduction (i.e., forming a built-in freewheeling diode), while the P-type doped region 4 injects holes into the N-base region during forward conduction, achieving conductance modulation. This alternating arrangement allows the device to achieve low-power switching under both bidirectional voltage conditions, while avoiding the increased chip area caused by a separate freewheeling diode.
[0040] In step S3, when forming the N-type doped region, the dopant element is preferably at least one of phosphorus (P) and arsenic (As). In one embodiment, the implantation energy of the N-type dopant ions is 60~120 keV, and the implantation dose is 1e15~3e15 cm⁻¹. -2 In another embodiment, both phosphorus and arsenic are used as dopants, with the arsenic ion implantation depth shallower than that of phosphorus ions, forming a shallow arsenic, deep phosphorus bilayer N-type doped structure. Phosphorus has a large diffusion coefficient in silicon, allowing for the formation of a deeper N-type region, which is beneficial for reducing the resistance during reverse conduction. Arsenic has a small diffusion coefficient, and its shallow implantation allows for a higher surface concentration, which is beneficial for forming a low contact resistance with the back metal. This shallow arsenic, deep phosphorus distribution further reduces the collector-emitter saturation voltage drop without sacrificing reverse conduction capability.
[0041] In step S3, when forming the P-type doped region, the dopant element can be boron (B). In one embodiment, the implantation energy of the P-type dopant ions can be 20~60 keV, and the dose can be 5e12~7e13 cm⁻¹. -2 Compared to the N-type region, the P-type region requires a 2-3 order of magnitude lower injection dose and lower injection energy. Therefore, its junction depth is typically less than 0.5 μm, forming a shallow P-type region, which is beneficial for maintaining a faster switching speed.
[0042] In the processes described above for forming N-type and P-type doped regions, the activation of impurity ions can be achieved through separate annealing, or by simultaneously activating both types of dopant in a one-step annealing process after the implantation of N-type and P-type dopant ions. As a preferred option, laser annealing can be used for activation, with annealing energy ranging from 1.8 J to 3.0 J. Laser annealing enables rapid localized heating, fully activating the dopant ions while avoiding excessive diffusion of the light arsenic / deep phosphorus distribution caused by prolonged high-temperature annealing, thus precisely maintaining the vertical gradient of light arsenic and deep phosphorus.
[0043] Both the N-type doped region 3 and the P-type doped region 4 can be strip-shaped, but are not limited to strips; they can also adopt other periodic geometric patterns such as grids or lattices. Preferably, the depth of the N-type doped region is between 0.5 μm and 2 μm, while the depth of the P-type doped region can be less than 0.5 μm. That is, the junction depth of the P-type doped region is significantly shallower than that of the N-type doped region. This depth difference ensures that during forward conduction, holes are mainly injected from the shallow P-type doped region, while during reverse conduction, electrons can flow rapidly through the deep N-type doped region, thus achieving a good trade-off between forward voltage drop and reverse recovery performance.
[0044] Step S4: A hydrogen ion buffer layer 5 is formed on the back side of substrate 1 using a hydrogen ion (proton) implantation process, see... Figure 5 The implantation energy and dosage are optimized to ensure that the peak implantation depth of hydrogen ions is located at a certain depth below the back side of the substrate. In this invention, a high-energy hydrogen implantation process of 600~800keV is selected, followed by furnace tube annealing at a temperature of 350℃~500℃ to activate hydrogen ions and form stable donor centers.
[0045] In step S4, when the hydrogen ion peak depth is too small, the hydrogen ion buffer layer is too close to the back metal layer, which can easily lead to an excessively high electric field peak and cause local breakdown. If the hydrogen ion peak depth is greater than 12 μm, the field cutoff effect of the buffer layer is weakened, and the turn-off loss increases. Preferably, the hydrogen ion implantation peak depth is 8 μm to 12 μm, for example, 9 μm, 10 μm, or 11 μm. Further, the depth of the hydrogen ion buffer layer is 3 μm to 30 μm, more preferably 10 μm to 20 μm, for example, 10 μm, 15 μm, or 20 μm.
[0046] Step S5: Form a back metal layer 6 on the back surface of substrate 1, see... Figure 6 A metal layer, such as a multilayer metal system of aluminum, titanium, nickel, and silver, is sequentially deposited or sputtered on the back side of substrate 1, and then alloyed and annealed to form an Al / Ti / Ni / Ag back metal layer 6 that has good ohmic contact with both the N-type doped region 3 and the P-type doped region 4. This back metal layer 6 serves as the collector / anode of the IGBT device.
[0047] The back-side fabrication method for the reverse-conducting IGBT device of the present invention involves adding a laser annealing process to the back side of the substrate under an oxygen-containing atmosphere to obtain an oxygen-doped region on the surface of the back side of the substrate. This oxygen-doped region plays a crucial role in subsequent metallization contacts and device turn-off processes. The oxygen atoms in this oxygen-doped region increase the hydrogen atom adsorption carrier, forming oxygen recombination centers with high thermal stability, thus alleviating the snapback problem that easily occurs in the forward conduction of the reverse-conducting IGBT device and improving wafer yield.
[0048] The present invention also provides a reverse-conducting IGBT device fabricated using the method of any of the above embodiments. The device includes: N-type substrate, with the front side of the substrate having the front structure of the IGBT device; Oxygen-doped region located on the back side of the substrate; The N-type doped region and the P-type doped region are located within the oxygen doped region, and the N-type doped region and the P-type doped region are arranged alternately side by side; A hydrogen ion buffer layer located on the back side of the substrate; and The back metal layer located on the back side of the substrate.
[0049] In a preferred embodiment, the oxygen-doped region of the reverse-conducting IGBT device has a depth of 1 μm to 2 μm, and the oxygen atom concentration in the oxygen-doped region is greater than 1 × 10⁻⁶. 16 atoms / cm 3 The peak depth of hydrogen ion implantation is 8μm~12μm, and the depth of the hydrogen ion buffer layer is 3μm~30μm.
[0050] Furthermore, the performance of the reverse-conducting IGBT device prepared by existing methods and the reverse-conducting IGBT device according to an embodiment of the present invention were tested. Figure 7 This is a comparison of emitter and collector leakage currents between chipsets fabricated using existing methods and chipsets fabricated using the method of this invention; the vertical axis represents leakage current, using a logarithmic scale, where a smaller value indicates lower leakage current and better device reliability. The chipset fabricated using the method of this invention reduces the single-phase failure rate of the emitter-collector leakage current (Ices) from 3% to 0%.
[0051] Figure 8 and Figure 9 The figures show the output characteristic curves of a reverse-conducting IGBT device fabricated using existing methods and a reverse-conducting IGBT device according to an embodiment of the present invention at different gate voltages Vg. The horizontal axis represents the drain-source voltage Vd, and the vertical axis represents the drain current Id. Multiple blue curves correspond to the Id-Vd characteristics at different Vg values; as Vg increases, the drain current Id rises. For devices fabricated using existing methods, the drain current Id curve shows a significant snapback at a drain-source voltage Vd of ~1V. (See figure...) Figure 8 The area within the dashed box. However, the drain current Id curve of the device in one embodiment of the present invention does not show the aforementioned snapback characteristic. This indicates that the reverse-conducting IGBT device obtained by the manufacturing method of the present invention does not exhibit a significant snapback problem when turned on.
[0052] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, various modifications, equivalent substitutions, or improvements can be made to the process parameters and structural dimensions without departing from the principles of the present invention, and these should also be considered within the scope of protection of the present invention.
[0053] The above description, in conjunction with specific preferred embodiments, provides a further detailed explanation of the present invention and should not be construed as limiting the specific implementation of the invention to these descriptions. It will be apparent to those skilled in the art that this application is not limited to the details of the above exemplary embodiments, and that the application can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of this application is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be embraced within this application. No reference numerals in the claims should be construed as limiting the scope of the claims.
Claims
1. A method for manufacturing the back side of a reverse-conducting IGBT device, characterized in that, Includes the following steps: An N-type substrate is provided, the front side of which has the front structure of an IGBT device; The back side of the substrate is annealed in an oxygen-containing atmosphere using a laser annealing process to form an oxygen-doped region on the back side of the substrate. Within the oxygen-doped region, N-type doped regions and P-type doped regions are formed respectively, with the N-type doped regions and the P-type doped regions being distributed alternately side by side. A hydrogen ion buffer layer is formed on the back side of the substrate; A back metal layer is formed on the back side of the substrate.
2. The method according to claim 1, characterized in that, The oxygen-containing atmosphere is a pure oxygen atmosphere or a mixture of oxygen and an inert gas.
3. The method according to claim 1, characterized in that, The oxygen volume fraction in the oxygen-containing atmosphere is greater than 20%.
4. The method according to claim 1, characterized in that, The energy of the laser annealing process is 2.0J~2.6J.
5. The method according to claim 1, characterized in that, The depth of the oxygen-doped region is 1 μm to 2 μm; and / or The oxygen atom concentration in the oxygen-doped region is greater than 1 × 10⁻⁶. 16 atoms / cm 3 .
6. The method according to claim 1, characterized in that, In the step of forming a hydrogen ion buffer layer on the back side of the substrate, a hydrogen ion implantation process is used, and the peak implantation depth of the hydrogen ions is 8 μm to 12 μm; and / or The depth of the hydrogen ion buffer layer is 3μm~30μm.
7. The method according to claim 1, characterized in that, In the step of forming an N-type doped region on the back side of the substrate, the doping element is at least one of phosphorus and arsenic.
8. The method according to claim 1, characterized in that, In the step of forming an N-type doped region on the back side of the substrate, the doping elements are phosphorus and arsenic, and the implantation depth of the arsenic is shallower than that of the phosphorus.
9. A reverse-conducting IGBT device, characterized in that, The reverse-conducting IGBT device is prepared using the method described in any one of claims 1 to 8, and comprises: An N-type substrate, the front side of which has the front structure of an IGBT device; Oxygen-doped region located on the back side of the substrate; The N-type doped region and the P-type doped region are located within the oxygen doped region, and the N-type doped region and the P-type doped region are arranged alternately side by side; A hydrogen ion buffer layer located on the back side of the substrate; and A back metal layer located on the back side of the substrate.
10. The reverse-conducting IGBT device according to claim 9, characterized in that, The depth of the oxygen-doped region is 1 μm to 2 μm; and / or The oxygen atom concentration in the oxygen-doped region is greater than 1 × 10⁻⁶. 16 atoms / cm 3 ; and / or The peak implantation depth of the hydrogen ions is 8 μm to 12 μm; and / or The depth of the hydrogen ion buffer layer is 3μm~30μm.