Reverse conducting IGBT (Insulated Gate Bipolar Translator) device, preparation method thereof, electronic equipment and vehicle

Abstract

The invention relates to a reverse conducting IGBT device and a preparation method thereof, electronic equipment and a vehicle, and the reverse conducting IGBT device is characterized in that a transition region is arranged between an IGBT region and a diode region of the reverse conducting IGBT device, the front surface structure of the transition region is consistent with the front surface structure of the diode region, and the back surface structure of the transition region is consistent with the back surface structure of the IGBT region. In the working mode of the diode, the anode emission efficiency is reduced, and the effect of reducing the reverse recovery current and the reverse recovery loss of the diode is achieved; in the IGBT working mode, more paths are provided for hole extraction, the turn-off speed of the IGBT is increased, and the turn-off loss of the device is reduced; meanwhile, the performance of the diode region and the IGBT region is improved, and the stability and reliability of the device are improved.

Description

Technical Field

[0001] This application relates to the field of semiconductor device technology, and in particular to a reverse-conducting IGBT device and its fabrication method, electronic equipment, and vehicles. Background Technology

[0002] Insulated-gate bipolar transistors (IGBTs) are now widely used in power electronic systems such as lighting circuits, switching power supplies, and electric vehicles. However, when IGBTs are used, a diode needs to be connected in reverse parallel, which leads to the problems of large size and low heat dissipation efficiency in traditional IGBT modules.

[0003] To reduce size and improve heat dissipation, the industry has proposed a reverse-conducting insulated-gate bipolar transistor (RC-IGBT) that integrates IGBTs and diodes on the same chip. This device saves chip area, reduces manufacturing and packaging costs, and improves device reliability.

[0004] However, current reverse-conducting IGBT devices have a high doping concentration on the back collector to achieve a smaller forward saturation voltage drop. This results in a slower hole extraction rate during turn-off due to the presence of a high concentration of holes, leading to increased turn-off losses. In order to achieve the required threshold voltage for the reverse-conducting IGBT device, the high doping concentration in the well regions of the IGBT and diode regions results in high carrier injection efficiency and high reverse recovery current during diode turn-on. This can easily cause device damage during turn-on, reducing device reliability. Summary of the Invention

[0005] This application provides a reverse-conducting IGBT device and its fabrication method, an electronic device, and a vehicle, which improves the performance, stability, and reliability of the reverse-conducting IGBT device, thereby at least partially solving the above-mentioned technical problems.

[0006] To achieve the above objectives, according to a first aspect of this application, a reverse-conducting IGBT device is provided, comprising at least one unit, wherein the unit comprises: An electric field region, wherein the front side of the electric field region is formed with a front structure of an IGBT region and a front structure of a diode region at intervals, and the back side of the electric field region is provided with a back structure of an IGBT region and a back structure of a diode region at corresponding intervals; A transition region, wherein the front structure of the transition region is formed on the front of the electric field region and located between the front structure of the IGBT region and the front structure of the diode region, and the back structure of the transition region is disposed on the back of the electric field region and located between the back structure of the IGBT region and the back structure of the diode region; The front structure of the transition region is consistent with the front structure of the diode region, and the back structure of the transition region is consistent with the back structure of the IGBT region.

[0007] Optionally, the well region doping concentration of the front structure of the transition region is the same as that of the front structure of the diode region, and the well region doping concentration of the front structure of the transition region is lower than that of the front structure of the IGBT region. The doping concentration of the collector region of the back structure of the transition region is the same as that of the collector region of the back structure of the IGBT region.

[0008] Optionally, the electric field region is a drift layer of a first conductivity type; or The electric field region includes a drift layer of a first conductivity type and a field termination layer of a first conductivity type, wherein the field termination layer is disposed on the back side of the drift layer.

[0009] Optionally, the front structure of the diode region includes: a diode region carrier storage layer of a first conductivity type, a diode region well region of a second conductivity type, a diode region trench gate structure, a diode region ohmic contact region of a second conductivity type, and a diode region emitter; the diode region carrier storage layer, diode region well region, diode region ohmic contact region, and diode region emitter are sequentially stacked and formed on the front side of the drift layer; the diode region trench gate structure extends into the drift layer through the diode region well region and the rear portion of the diode region carrier storage layer. The front structure of the transition region includes: a transition region carrier storage layer of a first conductivity type, a transition region well region of a second conductivity type, a transition region trench gate structure, a transition region ohmic contact region of a second conductivity type, and a transition region emitter; the transition region carrier storage layer, the transition region well region, the transition region ohmic contact region, and the transition region emitter are stacked sequentially on the front side of the drift layer; the transition region trench gate structure extends into the drift layer through the rear portion of the transition region well region and the transition region carrier storage layer.

[0010] Optionally, the back structure of the IGBT region includes: an IGBT region collector region of the second conductivity type and an IGBT region collector electrode; the field termination layer, the IGBT region collector region and the IGBT region collector electrode are sequentially stacked on the back of the drift layer; The back structure of the transition region includes: a transition region collector region of the second conductivity type and a transition region collector electrode; the field termination layer, the transition region collector region and the transition region collector electrode are stacked sequentially on the back of the drift layer.

[0011] Optionally, the doping concentration of the transition region collector area is the same as that of the IGBT region collector area.

[0012] Optionally, the doping concentration of the transition region collector is 1E18-5E19 cm⁻¹. -3 The junction depth is 0.5-1 μm.

[0013] Optionally, the front structure of the IGBT region includes: an IGBT region carrier storage layer of a first conductivity type, an IGBT region well region of a second conductivity type, a channel emitter region of a first conductivity type, an IGBT region trench gate structure, an IGBT region ohmic contact region of a second conductivity type, an IGBT region contact hole, a dielectric layer, and an IGBT region emitter; The IGBT region carrier storage layer is disposed on the front side of the drift layer; the IGBT region well region is located on the IGBT region carrier storage layer, and the channel emitter region and the IGBT region ohmic contact region are located on the IGBT region well region; the IGBT region trench gate structure extends into the drift layer through the IGBT region well region and the rear portion of the IGBT region carrier storage layer. The dielectric layer is disposed on the IGBT region trench gate structure; one end of the IGBT region contact hole penetrates the dielectric layer to form the IGBT region ohmic contact region, and the other end contacts the IGBT region emitter; the IGBT region emitter covers the dielectric layer.

[0014] Optionally, the doping concentration of the transition region well is the same as that of the diode region well, and the doping concentration of the transition region well is less than that of the IGBT region well.

[0015] Optionally, the back structure of the diode region includes: a diode region collector region of a first conductivity type and a diode region collector electrode; the field termination layer, the diode region collector region and the diode region collector electrode are sequentially stacked on the back of the drift layer.

[0016] Optionally, the drift layer includes a transition region lifetime control region corresponding to the transition region and a diode region lifetime control region corresponding to the diode region.

[0017] Optionally, the drift layer includes an IGBT region lifetime control region corresponding to the IGBT region.

[0018] Optionally, the first conductivity type is N-type and the second conductivity type is P-type; or, the first conductivity type is P-type and the second conductivity type is N-type.

[0019] Optionally, it includes multiple units spaced apart, with a transition zone between adjacent units.

[0020] According to a second aspect of this application, a method for fabricating a reverse-conducting IGBT device is provided, comprising: A semiconductor substrate is provided, the semiconductor substrate having an electric field region; In the electric field region, the front structure of the IGBT region, the front structure of the transition region, and the front structure of the diode region are arranged sequentially on the front side, so that the front structure of the transition region and the front structure of the diode region are consistent. On the back side of the electric field region, a back structure of the IGBT region, a back structure of the transition region, and a back structure of the diode region are prepared in sequence, so that the back structure of the transition region is consistent with the back structure of the IGBT region.

[0021] Optionally, the step of fabricating a front structure of the IGBT region, a front structure of the transition region, and a front structure of the diode region arranged sequentially on the front side of the electric field region, such that the front structure of the transition region and the front structure of the diode region are identical, includes: In the electric field region, a terminal field limiting ring and a carrier storage layer are formed by ion implantation on the front side and a high-temperature push trap, respectively; wherein, the carrier storage layer includes an IGBT region carrier storage layer of the first conductivity type, a transition region carrier storage layer of the first conductivity type, and a diode region carrier storage layer of the first conductivity type arranged in sequence; On the front side of the electric field region, trenches corresponding to the IGBT region, transition region and diode region are formed by photolithography and reactive ion etching. After growing gate oxide in the trenches, polysilicon is deposited. A transition region well region and a diode well region of the second conductivity type are formed on the transition region carrier storage layer and the diode region carrier storage layer by a first ion implantation; and an IGBT region well region of the second conductivity type is formed on the IGBT region carrier storage layer by a second ion implantation. In the gate trench region of the IGBT region, a channel emitter region of the first conductivity type is formed by ion implantation and high-temperature push-sinking. Etching removes the insulating dielectric layer of the transition region and diode region to form transition region contact holes and diode region contact holes. Ion implantation is then used to form a second conductivity type of ohmic contact region at the bottom of the transition region contact holes and diode region contact holes. The ohmic contact region includes a transition region ohmic contact region of the second conductivity type and a diode region ohmic contact region of the second conductivity type. Etching also removes the insulating dielectric layer of the IGBT region to form IGBT region contact holes. Ion implantation is then used to form a second conductivity type of IGBT region ohmic contact region at the bottom of the IGBT region contact holes. Emitter metal is deposited on the front side of the electric field region to form a front structure of the IGBT region, a front structure of the transition region, and a front structure of the diode region arranged in sequence, so that the front structure of the transition region and the front structure of the diode region are consistent; wherein, the emitter includes the emitter of the IGBT region, the emitter of the transition region, and the emitter of the diode region arranged in sequence.

[0022] Optionally, the doping concentration of the transition region well is the same as that of the diode region well, and the doping concentration of the transition region well is less than that of the IGBT region well.

[0023] Optionally, after the gate trench region of the IGBT region is formed into a channel emitter region through ion implantation and high-temperature push-well, the following method is further included: A local lifetime control region is formed within the electric field region by light ion irradiation, wherein the local lifetime control region includes a transition region lifetime control region corresponding to the transition region and a diode region lifetime control region corresponding to the diode region. Alternatively, a global lifetime control region corresponding to the IGBT region, transition region, and diode region can be formed within the electric field region by electron irradiation.

[0024] Optionally, the step of fabricating a back-side structure of the IGBT region, a back-side structure of the transition region, and a back-side structure of the diode region arranged sequentially on the back side of the electric field region, such that the back-side structure of the transition region is consistent with the back-side structure of the IGBT region, includes: A field termination layer is formed by ion implantation on the back side of the drift layer included in the electric field region; Ion implantation is performed on the field termination layer corresponding to the IGBT region and the transition region to form a collector region of a second conductivity type, wherein the collector region of the second conductivity type includes an IGBT region collector region and a transition region collector region; ion implantation is performed on the field termination layer corresponding to the diode region to form a diode region collector region of a first conductivity type. Collector metal is deposited on the back side of the drift layer to form a back side structure of the IGBT region, a back side structure of the transition region, and a back side structure of the diode region arranged in sequence, so that the back side structure of the transition region is consistent with the back side structure of the IGBT region; wherein, the collector includes the IGBT region collector, the transition region collector, and the diode region collector arranged in sequence.

[0025] Optionally, the doping concentration of the transition region collector area is the same as the doping concentration of the IGBT region collector area.

[0026] Optionally, the doping concentration of the transition region collector is 1E18-5E19 cm⁻¹. -3 The junction depth is 0.5-1 μm.

[0027] Optionally, the first conductivity type is N-type and the second conductivity type is P-type; or, when the first conductivity type is P-type, the second conductivity type is N-type.

[0028] According to a third aspect of this application, an electronic device is also provided, including the reverse-conducting IGBT device as described above.

[0029] According to a fourth aspect of this application, a vehicle is also provided, including the electronic equipment described above, or the reverse-conducting IGBT device described above.

[0030] The reverse-conducting IGBT device of this application embodiment includes at least one unit, the unit comprising: an electric field region, wherein the front side of the electric field region has a front structure of the IGBT region and a front structure of the diode region spaced apart, and the back side of the electric field region has a corresponding back structure of the IGBT region and a back structure of the diode region spaced apart; and a transition region, wherein the front structure of the transition region is formed on the front side of the electric field region and located between the front structures of the IGBT region and the diode region, and the back structure of the transition region is located on the back side of the electric field region and located between the back structures of the IGBT region and the diode region; wherein the front structure of the transition region is consistent with the front structure of the diode region, and the back structure of the transition region is consistent with the back structure of the IGBT region; by making the front structure of the transition region consistent with the front structure of the diode region and the back structure of the transition region consistent with the back structure of the IGBT region, the anode emission efficiency is reduced in diode operating mode, thereby reducing the reverse recovery current and reverse recovery loss of the diode; more paths are provided for hole extraction in IGBT operating mode, accelerating the turn-off speed of the IGBT and reducing the turn-off loss of the device; thus simultaneously improving the performance of the diode region and the IGBT region, and improving the stability and reliability of the device.

[0031] Other features and advantages of this application will be described in detail in the following detailed description section. Attached Figure Description To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0032] To gain a more complete understanding of this application and its beneficial effects, the following description will be provided in conjunction with the accompanying drawings, wherein the same reference numerals in the following description denote the same parts.

[0033] Figure 1 This is a cross-sectional view of the reverse-conducting IGBT device provided in Embodiment 1 of the exemplary embodiments disclosed in this application; Figure 2 This is a cross-sectional view of the reverse-conducting IGBT device provided in Embodiment 2 of the exemplary embodiments disclosed in this application; Figure 3 This is a cross-sectional view of the reverse-conducting IGBT device provided in Embodiment 3 of the exemplary embodiments disclosed in this application; Figure 4 This is a top view of the overall structure of the reverse-conducting IGBT device provided in the exemplary embodiments disclosed in this application; Figure 5 This is a flowchart of a method for fabricating a reverse-conducting IGBT device provided in an exemplary embodiment of this application; Figure 6 This is a flowchart of the method for fabricating the front structure in the fabrication method of the reverse-conducting IGBT device provided in the exemplary embodiments of this application; Figure 7 This is a flowchart of the method for fabricating the back structure in the fabrication method of the reverse-conducting IGBT device provided in the exemplary embodiments of this application; Figures 8-12 This is a schematic diagram of the fabrication process of the reverse-conducting IGBT device in an exemplary embodiment disclosed in this application.

[0034] Explanation of reference numerals in the attached figures: 100. Transition region; 101. Transition region emitter; 110. Transition region well region; 111. Transition region carrier storage layer; 71. Transition region polysilicon; 141. Transition region collector region; 161. Transition region collector electrode; 200. IGBT region; 2. IGBT region contact hole; 3. Dielectric layer; 4. IGBT region ohmic contact region; 5. Channel emitter region; 6. IGBT region well region; 72. IGBT region polysilicon; 8. IGBT region carrier storage layer; 9. Gate oxide layer; 142. IGBT region collector region; 162. IGBT region collector electrode; 300, Diode region; 103, Diode region emitter; 130, Diode region well region; 113, Diode region carrier storage layer; 73, Diode region polysilicon; 15, Diode region collector region; 163, Diode region collector. 400. Electric field region; 12. Drift layer; 13. Field termination layer; 500, Terminal Area; 1. Emitter; 7. Polysilicon; 10. Well region corresponding to the transition region and diode region; 11. Carrier storage layer corresponding to the transition region and diode region; 14. Collector region corresponding to the IGBT region and transition region; 16. Collector; 17. Lifetime control region; 18, 19, 20, and 21 are all photoresist. Detailed Implementation

[0035] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the protection scope of this application.

[0036] The following is a description of some terms used in the embodiments of this application: N-type semiconductor refers to an intrinsic semiconductor doped with donor impurities. N-type includes N+ and N- types, with N+ being highly doped and N- being lightly doped. P-type semiconductor refers to an intrinsic semiconductor doped with acceptor impurities. P-type includes P+ and P- types, with P+ being highly doped and P- being lightly doped. The dopant element in the P-type doped region can be boron (B) or boron fluoride (BF2), etc., while the dopant element in the N-type doped region can be phosphorus (P), arsenic (As), or hydrogen (H), etc., without specific limitations. A reverse-conducting IGBT device includes an IGBT region and a diode region, wherein the diode can be a freewheeling diode (FWD) or a fast recovery diode (FRD). According to the first aspect disclosed in this application, a reverse-conducting IGBT device is provided. Please refer to [link to relevant documentation]. Figure 1 , Figure 1 This is a cross-sectional view of the reverse-conducting IGBT device of Embodiment 1 provided in Embodiment 1 of this application.

[0037] A reverse-conducting IGBT device includes at least one unit, said unit comprising: An electric field region 400 is provided, wherein the front side of the electric field region 400 is provided with a front structure of an IGBT region 200 and a front structure of a diode region 300 at intervals, and the back side of the electric field region 400 is provided with a back structure of an IGBT region 200 and a back structure of a diode region 300 at intervals. A transition region 100, wherein the front structure of the transition region 100 is formed on the front of the electric field region 400 and located between the front structure of the IGBT region 200 and the front structure of the diode region 300, and the back structure of the transition region 100 is disposed on the back of the electric field region 400 and located between the back structure of the IGBT region 200 and the back structure of the diode region 300. The front structure of the transition region 100 is consistent with the front structure of the diode region 300, and the back structure of the transition region 100 is consistent with the back structure of the IGBT region 200.

[0038] Specifically, existing reverse-conducting IGBT devices include an IGBT region and a diode region, while this application uses an IGBT region 200 and a diode region 300 spaced apart, with a transition region 100 provided between the IGBT region 200 and the diode region 300. Please refer to [link to relevant documentation]. Figure 1 It is understood that the reverse-conducting IGBT device of Embodiment 1 provided in this application includes three sections disposed on the electric field region 400: left, middle, and right, corresponding sequentially to the IGBT region 200, the transition region 100, and the diode region 300. For example... Figure 1 The central part shown is the electric field region 400, and the IGBT region 200 includes the front structure of the IGBT region 200 located on the front side of the electric field region 400 (e.g., Figure 1 The upper left portion shown) and the back structure of the IGBT region 200 located on the back of the electric field region 400 (as shown in the upper left portion ... Figure 1 (As shown in the lower left part); the transition region 100 includes the front structure of the transition region 100 located on the front side of the electric field region 400 (such as...). Figure 1 The upper middle part shown) and the back structure of the transition region 100 located on the back of the electric field region 400 (as shown) Figure 1 (As shown in the lower middle part); the diode region 300 includes the front structure of the diode region 300 located on the front side of the electric field region 400 (e.g., the lower middle part); Figure 1 The upper right portion shown) and the back structure of the diode region 300 located on the back of the electric field region 400 (as shown in the figure). Figure 1 (The lower right part is shown).

[0039] From the structural perspective of the reverse-conducting IGBT device, the front structure of the transition region 100 in this application is consistent with the front structure of the diode region 300. This means that, along the transverse cross-section of the reverse-conducting IGBT device (transverse refers to the arrangement direction of multiple units), their structures are identical, both being the same front structure, and the front structure of the diode region 300 corresponds one-to-one with the front structure of the transition region 100. Along the vertical direction of the reverse-conducting IGBT device (vertical direction perpendicular to the front of the electric field region), the front structure of the transition region 100 corresponds one-to-one with the front structure of the diode region 300, and their thicknesses can be the same. In other words, in the actual fabrication process, the front structure of the transition region 100 and the front structure of the diode region 300 can be fabricated together using the same process. Along the transverse direction of the reverse-conducting IGBT device, the length of the front structure of the transition region 100 and the length of the front structure of the diode region 300 can be the same or different.

[0040] From the structural perspective of the reverse-conducting IGBT device, the back structure of the transition region 100 in this application is consistent with the back structure of the IGBT region 200. This means that, along the transverse cross-section of the reverse-conducting IGBT device (transverse refers to the arrangement direction of multiple units), their structures are identical, both being the same back structure, and the back structure of the IGBT region 200 corresponds one-to-one with the back structure of the transition region 100. Along the vertical direction of the reverse-conducting IGBT device (vertical perpendicular to the back of the electric field region), the back structure of the transition region 100 corresponds one-to-one with the back structure of the IGBT region 200, and their thicknesses can be the same. In other words, in the actual fabrication process, the back structure of the transition region 100 and the back structure of the IGBT region 200 can be fabricated together using the same process. Along the transverse direction of the reverse-conducting IGBT device, the length of the back structure of the transition region 100 and the back structure of the IGBT region 200 can be the same or different.

[0041] The novel reverse-conducting IGBT device provided in this application, based on existing reverse-conducting IGBT devices, achieves reduced anode emission efficiency in diode operating mode, thereby reducing the reverse recovery current and reverse recovery loss of the diode; it also provides more paths for hole extraction in IGBT operating mode, accelerating the IGBT turn-off speed and reducing the device's turn-off loss; and simultaneously improves the performance of both the diode and IGBT regions, enhancing the device's stability and reliability.

[0042] In some embodiments, the well region doping concentration of the front structure of the transition region 100 is the same as the well region doping concentration of the front structure of the diode region 300, and the well region doping concentration of the front structure of the transition region 100 is lower than the well region doping concentration of the front structure of the IGBT region 200. The doping concentration of the collector region of the back structure of the transition region 100 is the same as that of the collector region of the back structure of the IGBT region 200.

[0043] Specifically, taking diode region 300 as the FRD region, the following explanation is provided: both the front-side structure of transition region 100 and the front-side structure of the FRD region have well regions with the same well region doping concentration. Furthermore, the well region doping concentration of transition region 100 and the FRD region is lower than that of the well region of IGBT region 200. This application utilizes a lower well region doping concentration in transition region 100 and the FRD region compared to the well region of IGBT region 200, which helps to reduce hole injection efficiency in diode operating mode, thereby reducing the reverse recovery current and reverse recovery loss of the diode. In actual fabrication processes, the front-side structure of transition region 100 and the well region of the front-side structure of the FRD region can be fabricated together. In the reverse-conducting IGBT device of this application, the front-side structure of transition region 100 is consistent with the front-side structure of the FRD region. The presence of the front-side structure of transition region 100 provides more paths for hole extraction during IGBT device turn-off, which helps to accelerate IGBT turn-off and reduce device turn-off loss.

[0044] In the reverse-conducting IGBT device of this application, the back-side structure of the transition region 100 is consistent with the back-side structure of the IGBT region 200. Both the back-side structure of the transition region 100 and the back-side structure of the IGBT region 200 have corresponding collector regions with the same doping concentration, which is beneficial to reducing the forward conduction voltage drop of the IGBT region and thus reducing the conduction loss of the IGBT region. In the actual fabrication process, the back-side structure of the transition region 100 and the collector regions of the back-side structure of the IGBT region 200 can be fabricated together.

[0045] In some embodiments, the electric field region 400 is a drift layer of a first conductivity type; Alternatively, the electric field region 400 may include a drift layer 12 of a first conductivity type and a field termination layer 13 of a first conductivity type, wherein the field termination layer 13 is disposed on the back side of the drift layer 12.

[0046] It is understood that the electric field region 400 is the drift layer 12, or the drift region. The electric field region 400 may also include the drift layer 12 and the field termination layer 13, which is also called the buffer layer. Specifically, the field termination layer 13 can be formed on the back side of the drift layer 12 by ion implantation.

[0047] In some embodiments, please continue reading Figure 1 The front structure of the diode region 300 includes: a diode region carrier storage layer 113 of a first conductivity type, a diode region well region 130 of a second conductivity type, a diode region trench gate structure, a diode region ohmic contact region of a second conductivity type, and a diode region emitter 103; the diode region carrier storage layer 113, the diode region well region 130, the diode region ohmic contact region, and the diode region emitter 103 are sequentially stacked on the front side of the drift layer 12; the diode region trench gate structure extends into the drift layer 12 after penetrating the diode region well region 130 and the diode region carrier storage layer 113.

[0048] The front structure of the transition region 100 includes: a transition region carrier storage layer 111 of the first conductivity type, a transition region well region 110 of the second conductivity type, a transition region trench gate structure, a transition region ohmic contact region of the second conductivity type, and a transition region emitter 101; the transition region carrier storage layer 111, the transition region well region 110, the transition region ohmic contact region, and the transition region emitter 101 are sequentially stacked on the front side of the drift layer 12; the transition region trench gate structure extends into the drift layer 12 after penetrating the transition region well region 110 and the transition region carrier storage layer 111.

[0049] Specifically, the trench gate structure is a gate structure formed by multiple trenches in a reverse-conducting IGBT device. It includes multiple trenches etched on the front side of the electric field region 400, a dense gate oxide layer grown on the inner wall of each trench, and a trench gate structure formed by depositing polysilicon or similar materials on the oxide layer within the trench. The diode region trench gate structure includes at least one trench, and may also include multiple trenches, which may be arranged with equal or unequal spacing. The transition region trench gate structure includes at least one trench, and may also include multiple trenches, which may be arranged with equal or unequal spacing.

[0050] Specifically, the fabrication process of the front structure of the diode region 300 includes etching a trench gate on the front side of the drift layer 12, ion implanting and high-temperature push-well forming a diode region carrier storage layer 113 of the first conductivity type on the front side of the drift layer 12 corresponding to the diode region, and then depositing a front-side emitter metal to form a diode region emitter 103. The fabrication process of the front structure of the transition region 100 is the same as above and will not be described again.

[0051] The front structure of the transition region 100 used in this application is the same as the front structure of the FRD region, that is, the front structures of the two correspond one-to-one and have the same thickness. In other words, in the manufacturing process, the front structure of the transition region 100 and the front structure of the FRD region can be generated using the same process steps. Specifically, the process involves: forming a diode trench gate structure and a diode trench gate structure on the front side of the drift layer 12 using processes such as etching; forming a carrier storage layer 11 of a first conductivity type transition region and a diode region on the front side of the drift layer 12 by ion implantation and high-temperature push-well formation, the carrier storage layer 11 including a diode region carrier storage layer 113 and a first conductivity type transition region carrier storage layer 111; then forming a second conductivity type diode region well region 130 and a transition region well region 110 on the diode region carrier storage layer 113 and the transition region carrier storage layer 111 by corresponding ion implantation; then forming a diode region ohmic contact region and a transition region ohmic contact region by corresponding ion implantation; and finally depositing front-side emitter metal to form a diode region emitter 103 and a transition region emitter 101.

[0052] In some embodiments, please continue reading Figure 1 The front structure of the IGBT region 200 includes: an IGBT region carrier storage layer 8 of the first conductivity type, an IGBT region well region 6 of the second conductivity type, a channel emitter region 5 of the first conductivity type, an IGBT region trench gate structure, an IGBT region ohmic contact region 4 of the second conductivity type, an IGBT region contact hole 2, a dielectric layer 3, and an IGBT region emitter 102. The IGBT region carrier storage layer 8 is formed on the front side of the drift layer 12; the IGBT region well region 6 is formed on the IGBT region carrier storage layer 8, and the channel emitter region 5 and the IGBT region ohmic contact region 4 are formed on the IGBT region well region 6; the IGBT region trench gate structure extends into the drift layer 12 through the rear portion of the IGBT region well region 6 and the IGBT region carrier storage layer 8. The dielectric layer 3 is disposed on the IGBT region trench gate structure; one end of the IGBT region contact hole 2 penetrates the dielectric layer 3 to form the IGBT region ohmic contact region 4, and the other end contacts the IGBT region emitter 102; the IGBT region emitter 102 covers the dielectric layer 3.

[0053] Specifically, the trench gate structure of the IGBT region is consistent with the trench gate structure of the transition region and the trench gate structure of the diode region. The trenches of the IGBT region trench gate structure can be arranged with equal or unequal spacing. In the actual manufacturing process, multiple trenches are etched on the front side of the drift layer 12 to form trench gate structures corresponding to the IGBT region 200, the transition region 100 and the diode region 300 in sequence; and a carrier storage layer doped with the first conductivity type is formed on the front side of the electric field region 400 through ion implantation and high-temperature push-in. This carrier storage layer includes the IGBT region carrier storage layer 8 corresponding to the IGBT region 200, the transition region carrier storage layer 111 corresponding to the transition region 100 and the diode region carrier storage layer 113 corresponding to the diode region 300. Next, a low-doped well region 10 of the second conductivity type is formed in the transition region 100 and the diode region 300 by ion implantation. The well region 10 includes the diode region well region 130 and the transition region well region 110. Then, the transition region 100 and the diode region 300 are photoresist blocked, and a second ion implantation is performed in the IGBT region 200 to form a high-doped IGBT region well region 6 of the second conductivity type.

[0054] The IGBT contact hole 2, dielectric layer 3, IGBT ohmic contact area 4, and channel emitter area 5 are manufactured using existing processes. Dielectric layer 3 is an insulating dielectric layer. The insulating structure of the dielectric layer can be Si3N4, SiO2, or other insulating structures; the specific material is not limited.

[0055] It should be noted that during the intermediate stages of the fabrication process, corresponding dielectric layers 3 were also present on the transition region 100 and the diode region 300. However, when the insulating dielectric layer was etched using a wet etching process to obtain the contact holes for the transition region and the diode region, relatively large rectangular holes were obtained. Figure 1 This is a cross-sectional view of the final prepared product, so Figure 1 The transition region and diode region contact holes and corresponding ohmic contact regions are not shown. In the process of fabricating the front structure, the front emitter metal is deposited last, which simultaneously generates the IGBT region emitter 102 corresponding to IGBT region 200, the transition region emitter 101 corresponding to transition region 100, and the diode region emitter 103 corresponding to diode region 300. In practical applications, the contact holes can be rectangular slots, trapezoidal slots, conical slots, or irregularly shaped slots.

[0056] In some embodiments, the doping concentration of the transition region well region 110 is the same as the doping concentration of the diode region well region 130, and the doping concentration of the transition region well region 110 is less than the doping concentration of the IGBT region well region 6.

[0057] Specifically, in a reverse-conducting IGBT device, when a reverse voltage is applied to the forward-biased diode, the PN junction does not instantly change from the on state to the off state. This is because a large number of minority carriers are stored in the high-resistivity region when the diode is on. Therefore, it takes a certain amount of time to completely extract or neutralize these minority carriers when the diode is off. In other words, the recovery of the reverse blocking capability takes a certain amount of time. This process is called the reverse recovery process, and the time used for this process is defined as the reverse recovery time trr.

[0058] Anode emission efficiency control technology controls the minority carrier concentration injected into the high-resistivity region by controlling the emission efficiency of the P+ region, thereby shortening the reverse extraction time. This application employs a lower well doping concentration in the transition region 100 and the FRD region compared to the well region of the IGBT region 200. This is beneficial for reducing the anode emission efficiency in diode operating mode, thus reducing the reverse recovery current spike and reverse recovery loss. In the reverse-conducting IGBT device of this application, the front-side structure of the transition region 100 is consistent with the front-side structure of the FRD region. The presence of the front-side structure of the transition region 100 provides more paths for hole extraction during IGBT turn-off, which helps to accelerate IGBT turn-off and reduce device turn-off losses.

[0059] In some embodiments, please continue reading Figure 1 The back structure of the IGBT region 200 includes: an IGBT region collector region 142 of the second conductivity type and an IGBT region collector electrode; the field termination layer 13, the IGBT region collector region 142 and the IGBT region collector electrode 162 are stacked sequentially on the back of the drift layer 12. The back structure of the transition region 200 includes: a transition region collector 141 of the second conductivity type and a transition region collector 161; the field termination layer 13, the transition region collector 141 and the transition region collector 161 are sequentially stacked on the back of the drift layer 12.

[0060] Specifically, a field termination layer 13 of a first conductivity type is formed by ion implantation on the back side of the drift layer 12. The field termination layer 13 corresponds to the IGBT region 200, the transition region 100, and the diode region 300. Then, an IGBT region collector region 142 of a second conductivity type is formed on the field termination layer 13 corresponding to the IGBT region 200 through ion implantation and a high-temperature push-well process. A transition region collector region 141 of a second conductivity type is formed on the field termination layer 13 corresponding to the transition region 100 through ion implantation and a high-temperature push-well process. Finally, the corresponding IGBT region collector electrode 162 and transition region collector electrode 161 are deposited.

[0061] The back-side structure of the transition region 100 used in this application is consistent with the back-side structure of the IGBT region, meaning that the back-side structures of the two correspond one-to-one and have the same thickness. In the manufacturing process, the back-side structure of the transition region 100 and the back-side structure of the IGBT region 200 can be generated using the same process steps. Specifically, this involves: forming a field termination layer 13 of a first conductivity type by ion implantation on the back side of the drift layer 12, the field termination layer 13 corresponding to the IGBT region 200, the transition region 100, and the diode region 300; forming a collector region 14 of a second conductivity type on the back side of the IGBT region and the transition region through a second conductivity type ion implantation and high-temperature push-well process, the collector region 14 including the transition region collector region 141 and the IGBT region collector region 142 formed together. Finally, a back-side collector metal is deposited to form the transition region collector electrode 161 and the IGBT region collector electrode 162.

[0062] In some embodiments, the doping concentration of the transition region collector region 141 is the same as the doping concentration of the IGBT region collector region 142.

[0063] Specifically, in the reverse-conducting IGBT device of this application, the back structure of the transition region 100 is consistent with the back structure of the IGBT region 200. The presence of a collector region with the same second conductivity type doped on the back of the transition region as the IGBT region is beneficial to reducing the forward conduction voltage drop of the IGBT region, thereby reducing the conduction loss of the IGBT region.

[0064] In some embodiments, the doping concentration of the transition region collector is 1E18-5E19 cm⁻¹. -3 The junction depth is 0.5-1 μm.

[0065] Specifically, the ion doping concentration of the collector region 14 of the second conductivity type is 1E18-5E19 cm⁻¹. -3 The junction depth is 0.5-1µm, which allows for control of the emission injection efficiency.

[0066] In some embodiments, please refer to Figure 1 The back structure of the diode 300 includes: a diode region collector 15 of a first conductivity type and a diode region collector 163; the field termination layer 13, the diode region collector 15 and the diode region collector 163 are sequentially stacked on the back of the drift layer 12.

[0067] Specifically, the diode region collector region 15 corresponding to the diode region and the collector region 14 corresponding to the IGBT region and the transition region are arranged on the same layer, but with different conductivity types. In the process of fabricating the back structure, the back collector metal is deposited last, which means that the IGBT region collector 162 corresponding to the IGBT region 200, the diode region collector 163 corresponding to the transition region 100, and the diode region collector 163 corresponding to the diode region 300 are formed together.

[0068] To further improve device performance, the reverse-conducting IGBT device of this application also employs lifetime control technology to form a lifetime control region within the device. Please refer to... Figure 2 , Figure 2 This is a cross-sectional view of the reverse-conducting IGBT device of Embodiment 2 provided in the exemplary embodiments disclosed in this application. The reverse-conducting IGBT device of Embodiment 2 provided in this application has a transition region lifetime control region corresponding to the transition region 100 and a diode region lifetime control region corresponding to the diode region formed in the drift layer 12.

[0069] Specifically, carrier lifetime control technology is one of the key technologies for reducing reverse recovery time. By introducing deep energy levels to generate recombination centers in the base region, the carrier lifetime is reduced, the total amount of stored charge in the base region during forward conduction is reduced, and the recombination of minority carriers during reverse turn-off is accelerated, thereby reducing the reverse recovery time. Carrier lifetime control technology can be divided into two categories according to the location of the introduced recombination centers: global carrier lifetime control and local carrier lifetime control technology.

[0070] Local lifetime control technology, commonly known as light ion irradiation, has received widespread research and attention as it is currently the only technology capable of achieving controllable local lifetime. Light ions primarily refer to H ions and He ions. Similar to electron irradiation, light ion irradiation utilizes irradiation-induced defects as recombination centers to reduce minority carrier lifetime. Light ions are atomic irradiation, with a mass much larger than that of electrons, resulting in a very short injection range. like Figure 2 As shown, this application can use local lifetime control technology to form a local lifetime control region 17 corresponding to the transition region 100 and the diode region inside the drift layer 12.

[0071] Please see Figure 3 In some embodiments, an IGBT region lifetime control region corresponding to the IGBT region 200 is formed within the drift layer 12.

[0072] Specifically, electron irradiation technology utilizes high-intensity electron irradiation to induce defects inside a diode, which then act as recombination centers to reduce minority carrier lifetime. The irradiation energy is typically chosen between 0.5 and 15 MeV. Within this energy range, electrons can completely penetrate the entire device, forming uniformly distributed induced defects inside. Electron irradiation primarily creates phosphorus vacancies, oxygen vacancies, and double vacancies within the diode, forming deep-level recombination centers at various locations within the corresponding silicon bandgap. For example... Figure 3 As shown, this application uses electron irradiation technology to form global lifetime control regions corresponding to IGBT region 200, transition region 100 and diode region 300 in drift layer 12.

[0073] In some embodiments, the first conductivity type is N-type and the second conductivity type is P-type; or, the first conductivity type is P-type and the second conductivity type is N-type.

[0074] Specifically, when the first conductivity type is N-type, the second conductivity type is P-type; and when the first conductivity type is P-type, the second conductivity type is N-type.

[0075] In other words, the first conductivity type and the second conductivity type are complementary. The dopant element in the P-type doped region can be boron (B) and boron fluoride (BF2), etc., while the dopant element in the N-type doped region can be phosphorus (P), arsenic (As) and hydrogen (H), etc., and there are no specific restrictions on either.

[0076] In some embodiments, the area ratio of the IGBT region to the diode region is 1:1 to 10:1, and the area ratio of the IGBT region to the diode region can be adjusted according to the actual situation.

[0077] The above provides a detailed description of the structure of at least one unit or cell of the reverse-conducting IGBT device provided in this application. In actual device products, it includes multiple units arranged in a lateral array, such as... Figure 4 As shown, Figure 4 This is a top view of the overall structure of the reverse-conducting IGBT device provided in the exemplary embodiments disclosed in this application.

[0078] In some embodiments, the reverse-conducting IGBT device provided in this application includes a plurality of units spaced apart, with a transition region provided between two adjacent units.

[0079] Specifically, the RC-IGBT device provided in this application includes multiple units arranged in a horizontal array, each unit including an IGBT region, a transition region, and a diode region. These multiple units are spaced apart, with a transition region between adjacent units. In other words, the RC-IGBT device provided in this application includes alternately spaced IGBT and diode regions arranged in an array along the horizontal direction of the device, with a transition region between adjacent IGBT and diode regions.

[0080] Please refer to the second aspect disclosed in this application. Figure 5 A method for fabricating a reverse-conducting IGBT device is provided, comprising: S500, A semiconductor substrate is provided, the semiconductor substrate having an electric field region 400; S600: On the front side of the electric field region 400, the front structure of the IGBT region 200, the front structure of the transition region 100, and the front structure of the diode region 300 are arranged sequentially, so that the front structure of the transition region 100 and the front structure of the diode region 300 are consistent. S700: On the back side of the electric field region 400, a back structure of the IGBT region 200, a back structure of the transition region 100, and a back structure of the diode region 300 are prepared in sequence, so that the back structure of the transition region 100 is consistent with the back structure of the IGBT region 200.

[0081] Specifically, the fabrication method of the reverse-conducting IGBT device provided in this application includes the following steps: providing a semiconductor substrate, which may be a silicon substrate; then, on the front side of the silicon substrate, through a series of processes including ion implantation, high-temperature push-in, photolithography, etching, oxidation, and deposition, to obtain a front structure of IGBT region 200, a front structure of transition region 100, and a front structure of diode region 300 arranged sequentially, wherein the front structure of transition region 100 and the front structure of diode region 300 are consistent. The silicon substrate is then flipped. Next, on the back side of the silicon substrate, through a series of processes including ion implantation, high-temperature push-in, and deposition, to obtain a back structure of IGBT region 200, a back structure of transition region 100, and a back structure of diode region 300 arranged sequentially, wherein the back structure of transition region 100 and the back structure of IGBT region 200 are consistent.

[0082] The fabrication method of the reverse-conducting IGBT device in this application results in a front structure of the transition region that is consistent with the front structure of the FRD region. The presence of the front structure of the transition region provides more paths for hole extraction during IGBT turn-off, which helps to accelerate IGBT turn-off and reduce device turn-off losses. Furthermore, the back structure of the transition region in the device is consistent with the back structure of the IGBT region, which helps to reduce the forward conduction voltage drop of the IGBT region, thereby reducing the conduction losses of the IGBT region.

[0083] In some embodiments, please refer to Figure 1 and Figure 6 , Figure 6 This is a flowchart of a method for fabricating the front structure in an exemplary embodiment of the reverse-conducting IGBT device disclosed in this application. The method involves fabricating the front structure of the IGBT region, the front structure of the transition region, and the front structure of the diode region sequentially arranged on the front side of the electric field region through ion implantation, high-temperature push-in, photolithography, etching, oxidation, and deposition. The front structure of the transition region is identical to the front structure of the diode region, including: S610, in the electric field region 400, a field-limiting ring and a carrier storage layer are formed in the front ion implantation and high-temperature push trap of the terminal region 500, respectively; wherein, the carrier storage layer includes an IGBT region carrier storage layer 8 of the first conductivity type, a transition region carrier storage layer 111 of the first conductivity type and a diode region carrier storage layer 113 of the first conductivity type arranged in sequence. S620. On the front side of the electric field region 400, trenches corresponding to the IGBT region 200, the transition region 100 and the diode region 300 are formed by photolithography and reactive ion etching. After growing gate oxide in the trenches, polysilicon 7 is deposited, including IGBT region polysilicon 72, transition region polysilicon 71 and diode region polysilicon 73. S630, a transition region well region 110 and a diode well region 130 of the second conductivity type are formed on the transition region carrier storage layer 111 and the diode region carrier storage layer 113 by a first ion implantation; and an IGBT region well region 6 of the second conductivity type is formed on the IGBT region carrier storage layer 8 by a second ion implantation. S640, A first conductivity type channel emitter region 5 is formed in the gate trench region of the IGBT region by ion implantation and high temperature push-sink; S650: Etch the insulating dielectric layer of the transition region 100 and the insulating dielectric layer of the diode region 300 to form a transition region contact hole and a diode region contact hole. At the bottom of the transition region contact hole and the diode region contact hole, form an ohmic contact region of a second conductivity type by ion implantation. The ohmic contact region includes a transition region ohmic contact region of a second conductivity type and a diode region ohmic contact region of a second conductivity type. Etch the IGBT region 200 to form an IGBT region contact hole 2. At the bottom of the IGBT region contact hole 2, form an IGBT region ohmic contact region 4 of a second conductivity type by ion implantation. S660. An emitter metal is deposited on the front side of the electric field region 400 to form a front structure of the IGBT region, a front structure of the transition region, and a front structure of the diode region arranged in sequence, so that the front structure of the transition region and the front structure of the diode region are consistent; wherein, the emitter 1 includes an IGBT region emitter 102, a transition region emitter 101, and a diode region emitter 103 arranged in sequence.

[0084] Specifically, based on the structure of the reverse-conducting IGBT device of this application, the main steps in the fabrication method of this application are described, including a series of processes to generate the front-side structure of the IGBT region, the front-side structure of the transition region, and the front-side structure of the diode region on the front side of the drift layer 12. Regarding the etching of the transition region 100 and the diode region 300 to form transition region contact holes and diode region contact holes, the transition region contact hole and the diode region contact hole can actually be a single, relatively large hole. The contact hole can be a rectangular groove, a trapezoidal groove, a conical groove, or an irregularly shaped groove, etc.

[0085] In some implementations, the doping concentration of the transition region well is the same as that of the diode region well, while the doping concentration of the transition region well is less than that of the IGBT region well. Specifically, a transition region is added between the IGBT and the diode region, with the front side of the transition region having the same P-well concentration as the diode region. This helps to reduce the anode emission efficiency in diode operating mode, thereby reducing the reverse recovery current spike and reverse recovery loss of the diode. In the reverse-conducting IGBT device of this application, the front structure of the transition region 100 is consistent with the front structure of the FRD region. The presence of the front structure of the transition region 100 provides more paths for hole extraction when the IGBT device is turned off, which helps to accelerate the turn-off of the IGBT and reduce the turn-off loss of the device.

[0086] In some implementations, after forming the channel emitter region in the gate trench region of the IGBT through ion implantation and high-temperature push-well, the following steps are also included: A local lifetime control region is formed within the electric field region by light ion irradiation. The local lifetime control region includes a transition region lifetime control region corresponding to the transition region and a diode region lifetime control region corresponding to the diode region. Alternatively, a global lifetime control region corresponding to the IGBT region, transition region, and diode region can be formed within the electric field region by electron irradiation.

[0087] Specifically, the fabrication method of the reverse-conducting IGBT device provided in this application can form a local lifetime control layer for lifetime control of the corresponding transition region and diode region through lifetime control technology, and can also form a global lifetime control layer for lifetime control of the entire device.

[0088] In some implementations, such as Figure 7 As shown, Figure 7 This is a flowchart of a method for fabricating a back-side structure in an exemplary embodiment of the present application for fabricating a reverse-conducting IGBT device. The method involves fabricating a back-side structure corresponding to the IGBT region, a transition region, and a diode region arranged sequentially on the back side of the electric field region, ensuring that the back-side structure of the transition region is consistent with the back-side structure of the IGBT region. This includes: S710, The electric field region includes a drift layer and a field termination layer, and the field termination layer is formed by ion implantation on the back side of the drift layer; S720. Ion implantation is performed on the field termination layer corresponding to the IGBT region and the transition region to form a collector region of the second conductivity type, wherein the collector region of the second conductivity type includes the collector region of the IGBT region and the collector region of the transition region; ion implantation is performed on the field termination layer corresponding to the diode region to form a collector region of the first conductivity type. S730. Deposit collector metal on the back side of the drift layer to form a back side structure of the IGBT region, a back side structure of the transition region, and a back side structure of the diode region arranged in sequence, so that the back side structure of the transition region is consistent with the back side structure of the IGBT region; wherein, the collector includes the IGBT region collector, the transition region collector, and the diode region collector arranged in sequence.

[0089] Specifically, based on the consistency of the back-side structure of the transition region and the IGBT region, the fabrication method of this application forms the collector region and collector electrode in the back-side structure together.

[0090] In some implementations, the doping concentration of the transition region collector area is the same as that of the IGBT region collector area. Specifically, the collector area of ​​the back structure of the transition region has the same doping concentration as the collector area of ​​the back structure of the IGBT region; this is beneficial for reducing the forward conduction voltage drop of the IGBT region, thereby reducing the conduction loss of the IGBT region.

[0091] In some implementations, the doping concentration in the transition region collector is 1E18-5E19 cm⁻¹. -3 The junction depth is 0.5-1 μm. Specifically, the preparation method provided in this application uses such a doping concentration to control the emission injection efficiency.

[0092] In some implementations, when the first conductivity type is N-type, the second conductivity type is P-type; when the first conductivity type is P-type, the second conductivity type is N-type.

[0093] The above preparation methods can be used to prepare materials with properties such as Figure 1 The reverse-conducting IGBT power device is shown. It is understood that the process steps and conditions in the above fabrication method can be set according to actual needs, and the order of the process steps can also be adjusted or changed based on actual conditions.

[0094] Please refer to them in order. Figures 8 to 12 This series of figures are schematic diagrams illustrating the fabrication process of the reverse-conducting IGBT device in an exemplary embodiment disclosed in this application. Figure 8 This is a schematic diagram of the fabrication process of the well region of the second conductivity type in the transition region and FRD region; Figure 9 This is a schematic diagram of the fabrication process of the well region, which is the second conductivity type in the IGBT region. Figure 10 This is a schematic diagram of the fabrication process of the channel emitter region, which is the first conductivity type in the IGBT region. Figure 11 This is a schematic diagram of the fabrication process of the contact holes and ohmic contact areas in the transition region and FRD region; Figure 12 This is a schematic diagram of the fabrication process of the IGBT contact hole and ohmic contact area. The following details the main steps of the specific fabrication process of the reverse-conducting IGBT device of this application, using the diode region as the FRD region: Step 1: Provide a silicon substrate, and form a 500 field-limiting ring in the terminal region within the silicon substrate by ion implantation and high-temperature push-trap.

[0095] Step 2: A carrier storage layer of the first conductivity type is formed on the front side of the silicon substrate by ion implantation and high-temperature push-in. The carrier storage layer includes an IGBT region carrier storage layer 8, a transition region carrier storage layer 111, and a diode region carrier storage layer 113.

[0096] Step 3: IGBT region trenches, transition region trenches, and FRD region trenches are formed on the front side of the silicon substrate using photolithography and reactive ion etching. The trenches can be arranged with equal or unequal spacing.

[0097] Step 4: Grow a dense gate oxide layer 9 on the inner wall of each trench. Specifically, to reduce crystal defects and impurities and grow a dense insulating oxide layer, a sacrificial oxide layer is first grown on the inner wall of each trench area through high-temperature oxidation. This sacrificial oxide layer is then removed using a wet etching process to ensure the smoothness and flatness of the insulating oxide layer. An insulating oxide layer is then grown on the inner wall of each trench area through high-temperature oxidation. The thickness of the insulating oxide layer is 800-1500 μm.

[0098] Step 5: Deposit polysilicon 7 of the first conductivity type on the oxide layer 9 in each trench. Specifically, polysilicon is deposited on the front side of the silicon substrate through a high-temperature furnace tube and in-situ doped to form polysilicon 7 of the first conductivity type. Figure 1 As shown, the polysilicon 7 includes the corresponding IGBT region polysilicon 72, the transition region polysilicon 71, and the FRD region polysilicon 73.

[0099] Step 6: A first-stage ion implantation is performed to form a lightly doped well region 10 of the second conductivity type in the transition region and the FRD region, specifically as follows: Figure 8 The process diagram is shown below. Among them, as... Figure 1 As shown, the low-doped well region 10 of the second conductivity type includes a diode region well region 130 and a transition region well region 110.

[0100] Step 7: Apply photoresist 18 to the transition region and FRD region, and perform secondary ion implantation in the IGBT region to form a highly doped IGBT well region 6 with the second conductivity type. Figure 9 The process diagram is shown below.

[0101] Step 8: A highly doped channel emitter region 5 of the first conductivity type is formed in the gate trench region of the IGBT region through ion implantation and high-temperature push-well formation. Specifically, as shown... Figure 10 As shown, an injection window for a channel emitter region 5 of the first conductivity type is formed in the gate trench region using a photoresist 19 mask. High-energy ions of the first conductivity type are injected into the injection window and pushed into the well at high temperature, thereby forming a channel emitter region 5 of the first conductivity type in the gate trench region of the IGBT region.

[0102] Step 9, as follows Figure 11 As shown, a wet etching process is used to etch the insulating dielectric layer to obtain contact holes for the transition region and the FRD region. By implanting ions of a second conductivity type into the contact holes, second conductivity type-doped ohmic contact regions are formed in the transition region and the FRD region. These contact holes are relatively large and are not shown in the figure. Label 20 in the figure represents the photoresist.

[0103] Step 10, as follows Figure 12 Dry etching is performed on the insulating dielectric layer 3 of the IGBT region to obtain the IGBT region contact hole 2. Second conductivity type ions are implanted into the IGBT region contact hole 2 to form the second conductivity type doped ohmic contact region 4 of the IGBT region. Label 21 in the figure represents photoresist.

[0104] Step 11: Finally, on the front side of the device after the above main steps, an emitter metal is deposited to obtain emitter 1. Specifically, a metal layer with a thickness of 1-5 μm is deposited on the front side of the silicon substrate. The metal is an aluminum / silicon alloy, an aluminum / silicon / copper alloy, or other materials, and is alloyed by hot annealing to form an ohmic contact between the highly doped silicon and the metal, reducing the contact resistance. Through the above steps Step 1 to Step 11, the front side structure of the reverse-conducting IGBT device of this application can be obtained, including the IGBT region front side structure, the transition region front side structure, and the FRD region front side structure arranged sequentially, and the transition region front side structure and the FRD region front side structure are consistent.

[0105] Step 12: Flip the substrate and ion implant the back side of the silicon substrate to form a field termination layer 13 of the first conductivity type.

[0106] Step 13: On the back side of the silicon substrate corresponding to the IGBT region and the transition region, a collector region or collector region 14 of the second conductivity type is formed by ion implantation of the second conductivity type and high-temperature push-in process; wherein, the ion doping concentration of the collector region of the second conductivity type is 1E18-5E19 cm⁻¹.-3 The junction depth is 0.5-1µm, which allows for control of the emission injection efficiency. The second conductivity type collector region 14 is formed only on the back side of the silicon substrate corresponding to the IGBT region and the transition region. The collector region 14 includes the transition region collector region 141 and the IGBT region collector region 142.

[0107] Step 14: Form a collector region 15 of the first conductivity type on the back side of the silicon substrate corresponding to the FRD region.

[0108] Step 15: After the above steps, collector metal is deposited on the back side of the silicon substrate to form collector 16, thereby obtaining the RC-IGBT device of this application. Collector 16 includes an IGBT region collector 162 corresponding to the IGBT region, a diode region collector 163 corresponding to the transition region 100, and a diode region collector 163 corresponding to the diode region 300; in fact, they are all formed together. The back side structure of the IGBT region of the RC-IGBT device obtained in this way is consistent with the back side structure of the transition region.

[0109] In some embodiments, between Step 8 and Step 9, the fabrication method of the reverse-conducting IGBT device further includes lifetime control of the device. Specifically, lifetime control technology can be used to form a local lifetime control region corresponding to the lifetime control of the transition region and the FRD region, or to form a global lifetime control region corresponding to the lifetime control of the entire device.

[0110] In summary, this application provides a novel reverse-conducting IGBT device and its fabrication method. A transition region is provided between the IGBT region and the FRD region, making the front structure of the transition region identical to that of the FRD region. The relatively low concentration of the second conductivity type doped well region in the transition region and the FRD region helps to reduce the anode emission efficiency in diode operating mode, thereby reducing the reverse recovery current spike and reverse recovery loss. The front structure of the transition region in the device is identical to that of the FRD region. In IGBT operating mode, the transition region provides a conduction path for hole flow during turn-off, which is beneficial for extraction and reduces device turn-off loss. The back structure of the transition region in the device is identical to that of the IGBT region. The presence of the same second conductivity type doped collector region on the back of the transition region as the IGBT region helps to reduce the forward conduction voltage drop of the IGBT region, thereby reducing the conduction loss of the IGBT region. The RC-IGBT device designed in this application can simultaneously improve the switching performance of the FRD and IGBT, enhancing the stability and reliability of the device.

[0111] According to a third aspect disclosed in this application, a reverse-conducting IGBT device is provided, which is prepared according to the above-described method for preparing a reverse-conducting IGBT device.

[0112] According to the fourth aspect disclosed in this application, an electronic device is provided, which includes the aforementioned reverse-conducting IGBT device. This electronic device possesses all the beneficial effects of the aforementioned reverse-conducting IGBT device, which will not be elaborated further herein.

[0113] According to the fifth aspect disclosed in this application, a vehicle is provided that includes the aforementioned electronic equipment, and the vehicle possesses all the beneficial effects of the aforementioned electronic equipment, which will not be elaborated further herein. The electronic equipment may be an IGBT module, etc.

[0114] The vehicle may be a gasoline-powered vehicle, a plug-in hybrid electric vehicle, or a new energy vehicle, etc., and this application does not make any specific restrictions.

[0115] In the description of this application, 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 features. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0116] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0117] The embodiments, implementation methods, and related technical features of this application can be combined and substituted for each other without conflict.

[0118] The above are merely preferred embodiments of this application and are not intended to limit this application in any way. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of this application without departing from the scope of the technical solution of this application shall still fall within the scope of the technical solution of this application.

Claims

1. A reverse conducting IGBT device, characterized by, The device comprises at least one unit, which comprises: a field region, a front surface of the field region being spaced apart from a front surface structure of an IGBT region and a front surface structure of a diode region, a back surface of the field region being correspondingly spaced apart from a back surface structure of the IGBT region and a back surface structure of the diode region; a transition region, a front surface structure of the transition region being formed on the front surface of the field region and located between the front surface structure of the IGBT region and the front surface structure of the diode region, a back surface structure of the transition region being formed on the back surface of the field region and located between the back surface structure of the IGBT region and the back surface structure of the diode region; wherein the front surface structure of the transition region is consistent with the front surface structure of the diode region, and the back surface structure of the transition region is consistent with the back surface structure of the IGBT region.

2. The reverse conducting IGBT device according to claim 1, characterized in that, The field region comprises a drift layer of a first conductivity type; the front surface structure of the diode region comprises a diode region carrier storage layer of the first conductivity type, a diode region well region of a second conductivity type, a diode region trench gate structure, a diode region ohmic contact region of the second conductivity type, and a diode region emitter; the diode region carrier storage layer, the diode region well region, the diode region ohmic contact region, and the diode region emitter are sequentially stacked on the front surface of the drift layer; the diode region trench gate structure extends into the drift layer after penetrating the diode region well region and the diode region carrier storage layer. The front surface structure of the transition region comprises a transition region carrier storage layer of the first conductivity type, a transition region well region of the second conductivity type, a transition region trench gate structure, a transition region ohmic contact region of the second conductivity type, and a transition region emitter; the transition region carrier storage layer, the transition region well region, the transition region ohmic contact region, and the transition region emitter are sequentially stacked on the front surface of the drift layer; the transition region trench gate structure extends into the drift layer after penetrating the transition region well region and the transition region carrier storage layer.

3. The reverse conducting IGBT device according to claim 1, characterized in that, The field region comprises a drift layer of a first conductivity type, and a field termination layer of the first conductivity type is arranged on the back surface of the drift layer; the back surface structure of the IGBT region comprises an IGBT region collector region of a second conductivity type and an IGBT region collector electrode; the field termination layer, the IGBT region collector region, and the IGBT region collector electrode are sequentially stacked on the back surface of the drift layer. The back surface structure of the transition region correspondingly comprises a transition region collector region of the second conductivity type and a transition region collector electrode; the field termination layer, the transition region collector region, and the transition region collector electrode are sequentially stacked on the back surface of the drift layer. The doping concentration of the transition region collector region is the same as that of the IGBT region collector region.

4. The reverse conducting IGBT device according to claim 2, characterized in that, The front surface structure of the IGBT region comprises an IGBT region carrier storage layer of the first conductivity type, an IGBT region well region of the second conductivity type, a channel emission region of the first conductivity type, an IGBT region trench gate structure, an IGBT region ohmic contact region of the second conductivity type, an IGBT region contact hole, a dielectric layer, and an IGBT region emitter. The IGBT region carrier storage layer is arranged on the front surface of the drift layer; the IGBT region well region is arranged on the IGBT region carrier storage layer, and the channel emission region and the IGBT region ohmic contact region are arranged on the IGBT region well region; the IGBT region trench gate structure extends into the drift layer after penetrating the IGBT region well region and the IGBT region carrier storage layer; The dielectric layer is arranged on the IGBT region trench gate structure; one end of the IGBT region contact hole penetrates the dielectric layer to form the IGBT region ohmic contact region, and the other end is in contact with the IGBT region emitter; the IGBT region emitter is arranged on the dielectric layer; The doping concentration of the transition region well region is the same as the doping concentration of the diode region well region, and the doping concentration of the transition region well region is less than the doping concentration of the IGBT region well region.

5. The reverse conducting IGBT device according to any one of claims 1 to 4, characterized in that The transition region is arranged between adjacent units.

6. A method of manufacturing a reverse conducting IGBT device, characterized by, The semiconductor substrate comprises: A semiconductor substrate is provided, and the semiconductor substrate has an electric field region; A front surface structure of an IGBT region, a front surface structure of a transition region and a front surface structure of a diode region are sequentially arranged on the front surface of the electric field region, so that the front surface structure of the transition region and the front surface structure of the diode region are consistent; A back surface structure of an IGBT region, a back surface structure of a transition region and a back surface structure of a diode region are sequentially arranged on the back surface of the electric field region, so that the back surface structure of the transition region and the back surface structure of the IGBT region are consistent.

7. The method of manufacturing a reverse conducting IGBT device according to claim 6, wherein The semiconductor substrate comprises: Ion implantation and high-temperature push well are performed on the front surface of the electric field region to form a terminal region field limiting ring and a carrier storage layer, respectively; wherein the carrier storage layer comprises an IGBT region carrier storage layer of a first conductivity type, a transition region carrier storage layer of the first conductivity type and a diode region carrier storage layer of the first conductivity type which are sequentially arranged; Trenches corresponding to the IGBT region, the transition region and the diode region are formed on the front surface of the electric field region by photolithography and reactive ion etching, and polycrystalline silicon is deposited after growing gate oxide in the trenches; A transition region well region of a second conductivity type and a diode well region of the second conductivity type are formed on the transition region carrier storage layer and the diode region carrier storage layer by one-time ion implantation; an IGBT region well region of the second conductivity type is formed on the IGBT region carrier storage layer by two-time ion implantation; A channel emission region of a first conductivity type is formed in the gate trench region of the IGBT region by ion implantation and high-temperature push well; etching the insulating medium layer of the transition region and the diode region to form a transition region contact hole and a diode region contact hole, and forming an ohmic contact region of the second conductive type at the bottom of the transition region contact hole and the diode region contact hole by ion implantation, wherein the ohmic contact region comprises a transition region ohmic contact region of the second conductive type and a diode region ohmic contact region of the second conductive type; and etching the IGBT region to form an IGBT region contact hole, and forming an IGBT region ohmic contact region of the second conductive type at the bottom of the IGBT region contact hole by ion implantation; depositing an emitter on the front surface of the electric field region to form a front surface structure of the IGBT region, a front surface structure of the transition region, and a front surface structure of the diode region arranged in sequence, and making the front surface structure of the transition region and the front surface structure of the diode region consistent; wherein the emitter comprises an IGBT region emitter, a transition region emitter, and a diode region emitter arranged in sequence; the doping concentration of the transition region well region is the same as the doping concentration of the diode region well region, and the doping concentration of the transition region well region is less than the doping concentration of the IGBT region well region.

8. The method of manufacturing a reverse conducting IGBT device according to claim 6, wherein the preparation of the back surface structure of the IGBT region, the back surface structure of the transition region, and the back surface structure of the diode region arranged in sequence in the back surface of the electric field region, and making the back surface structure of the transition region and the back surface structure of the IGBT region consistent, comprises: forming a field termination layer by ion implantation on the back surface of a drift layer included in the electric field region; forming a collector region of the second conductive type by ion implantation on the field termination layer corresponding to the IGBT region and the transition region, wherein the collector region of the second conductive type comprises an IGBT region collector region and a transition region collector region; and forming a diode region collector region of the first conductive type by ion implantation on the field termination layer corresponding to the diode region; depositing a collector electrode on the back surface of the drift layer to form the back surface structure of the IGBT region, the back surface structure of the transition region, and the back surface structure of the diode region arranged in sequence, and making the back surface structure of the transition region and the back surface structure of the IGBT region consistent; wherein the collector electrode comprises an IGBT region collector electrode, a transition region collector electrode, and a diode region collector electrode arranged in sequence; the doping concentration of the transition region collector region is the same as the doping concentration of the IGBT region collector region.

9. An electronic device, comprising: The reverse-conducting IGBT device of any one of claims 1 to 5.

10. A vehicle characterized by comprising: The electronic device of claim 9, or the reverse-conducting IGBT device of any one of claims 1 to 5.

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