Reverse conducting insulated gate bipolar transistor
By setting a hole injection region in the reverse-conducting insulated-gate bipolar transistor, the problem of long-term high emitter-collector voltage is solved, achieving rapid reverse turn-on and performance improvement.
Patent Information
- Application Number
- CN202511753341.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-26
- Publication Date
- 2026-02-13
AI Technical Summary
During the reverse turn-on phase, the emitter-collector voltage of a reverse-conducting insulated-gate bipolar transistor remains at a high level for a relatively long time, affecting its reverse turn-on performance.
A hole injection region is provided in a reverse-conducting insulated-gate bipolar transistor. By providing holes that move toward the collector structure, the drift region is rapidly recovered from the depletion state. The transistor includes a collector structure, a drift region, a carrier storage region, a base region, and a first conductivity type emitter region stacked sequentially along a first direction, as well as a first trench and a second trench spaced apart along a second direction. The trench contains a hole injection region and a gate structure.
This accelerates the reverse turn-on process of the reverse-conducting insulated-gate bipolar transistor, improves its reverse turn-on performance, and reduces costs.
Smart Images
Figure CN121531731A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of semiconductor technology, and in particular to a reverse-conducting insulated-gate bipolar transistor. Background Technology
[0002] The reverse-conducting insulated-gate bipolar transistor (RC-IGBT) is an advanced power semiconductor device that integrates an insulated-gate bipolar transistor (IGBT) and a free-wheeling diode (FWD) on a single chip. It is suitable for applications requiring high power density, high efficiency, and miniaturization.
[0003] In related technologies, when a reverse-conducting insulated-gate bipolar transistor (IGBT) is in the forward blocking state, its P-type drift region is in a depleted state. When the IGBT transitions from the forward blocking state to the reverse turning-on state, the depleted P-type drift region cannot recover quickly from the depleted state. As a result, during the reverse turning-on phase, the emitter-collector voltage remains at a high level for a relatively long time, affecting the reverse turning-on performance of the IGBT. Summary of the Invention
[0004] This application provides a reverse-conducting insulated-gate bipolar transistor to solve the technical problem in the prior art where the emitter-collector voltage of the reverse-conducting insulated-gate bipolar transistor remains at a high level for a long time during the reverse turn-on phase, affecting the reverse turn-on performance of the reverse-conducting insulated-gate bipolar transistor.
[0005] This application provides a reverse-conducting insulated-gate bipolar transistor, comprising: The collector structure, drift region, carrier storage region, base region, and emitter region of first conductivity type are stacked sequentially along a first direction, and the first trench, second trench, and second trench are spaced apart along a second direction, wherein the first direction is perpendicular to the second direction. Both the first trench and the second trench extend from the side of the first conductivity type emitter region away from the base region into the drift region; Both the first trench and the second trench have hole injection regions on the side away from the drift region. The hole injection regions are used to provide holes that move toward the collector structure when the reverse-conducting insulated gate bipolar transistor is turned on in reverse. A gate structure is provided on the side of the hole injection region away from the drift region.
[0006] In one embodiment of this application, the collector structure includes a first conductivity type collector region and a second conductivity type collector region, with a preset interval between the first conductivity type collector region and the second conductivity type collector region, and the first conductivity type and the second conductivity type are different; A second conductivity type buffer layer is provided between the first conductivity type collector area and the drift area, and a first conductivity type buffer layer is provided between the second conductivity type collector area and the drift area. The second conductivity type buffer layer covers the first conductivity type collector area, and the first conductivity type buffer layer covers the second conductivity type collector area. The doping concentration of the first conductivity type collector region is greater than the doping concentration of the second conductivity type buffer layer, and the doping concentration of the second conductivity type collector region is greater than the doping concentration of the first conductivity type buffer layer.
[0007] In one embodiment of this application, the drift region is a second conductivity type drift region, and the doping concentration of the second conductivity type drift region is lower than the doping concentration of the first conductivity type buffer layer.
[0008] In one embodiment of this application, the carrier storage region is a first conductivity type carrier storage region, wherein the doping concentration of the first conductivity type carrier storage region is greater than the doping concentration of the second conductivity type drift region and lower than the doping concentration of the first conductivity type buffer layer.
[0009] In one embodiment of this application, the base region is a second conductivity type base region, and the doping concentration of the second conductivity type base region is greater than the doping concentration of the first conductivity type carrier storage region and lower than the doping concentration of the first conductivity type collector region.
[0010] In one embodiment of this application, the reverse-conducting insulated-gate bipolar transistor further includes a second conductivity type emitter region, which penetrates the first conductivity type emitter region and the base region. The doping concentration of both the first conductivity type emitter region and the second conductivity type emitter region is greater than the doping concentration of the second conductivity type buffer layer.
[0011] In one embodiment of this application, the gate structure includes an insulating dielectric layer and a gate material layer; In the first trench, the insulating dielectric layer covers the inner sidewall of the first trench, and the gate material layer fills the trench formed by the insulating dielectric layer; In the second trench, the insulating dielectric layer covers the inner sidewall of the second trench, and the gate material layer fills the trench formed by the insulating dielectric layer.
[0012] In one embodiment of this application, the gate material layer is deposited using polysilicon material, and the doping concentration of the gate material layer is greater than the doping concentration of the second conductivity type buffer layer.
[0013] In one embodiment of this application, the hole injection region is a second conductivity type hole injection region, wherein the doping concentration of the second conductivity type hole injection region is greater than the doping concentration of the first conductivity type carrier storage region and less than the doping concentration of the first conductivity type collector region.
[0014] In one embodiment of this application, when the reverse-conducting insulated-gate bipolar transistor is in a forward blocking state, the gate material layer is grounded and the drift region is in a depletion state; the reverse-conducting insulated-gate bipolar transistor refers to the reverse-conducting insulated-gate bipolar transistor changing from a forward blocking state to a reverse-on state.
[0015] The beneficial effects of this application are as follows: The reverse-conducting insulated-gate bipolar transistor proposed in this application includes: a collector structure, a drift region, a carrier storage region, a base region, and a first conductivity type emitter region stacked sequentially along a first direction, and a first trench and a second trench spaced apart along a second direction, the first direction being perpendicular to the second direction; both the first trench and the second trench extend from the side of the first conductivity type emitter region away from the base region into the drift region; both the side of the first trench away from the drift region and the side of the second trench away from the drift region are provided with hole injection regions, which are used to provide holes that move toward the collector structure when the reverse-conducting insulated-gate bipolar transistor is turned on in reverse; a gate structure is provided on the side of the hole injection region away from the drift region. Understandably, by setting the aforementioned hole injection region, holes that can move toward the collector structure can be provided when the reverse-conducting insulated-gate bipolar transistor (IGBT) turns on in reverse, i.e., when the IGBT changes from the forward blocking state to the reverse turning-on state. This allows the drift region to recover from the depletion state as quickly as possible, accelerates the reverse turning-on process, and improves the reverse turning-on performance of the IGBT. Attached Figure Description
[0016] 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. It is obvious that the drawings described below are merely some embodiments of this application, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort.
[0017] In the attached diagram: Figure 1 This is a schematic diagram of the structure of a reverse-conducting insulated-gate bipolar transistor provided in an embodiment of this application; Figure 2A comparison diagram of the reverse turn-on curves of the reverse-conducting insulated-gate bipolar transistor provided in this application and the reverse-conducting insulated-gate bipolar transistor in the prior art.
[0018] The attached figures are labeled as follows: 1-Second conductivity type collector region; 2-First conductivity type collector region; 3-First conductivity type buffer layer; 4-Second conductivity type buffer layer; 5-Drift region; 6-Carrier storage region; 7-Insulating dielectric layer; 8 - Base region; 9 - Emitter region of the first conductivity type; 10 - Emitter region of the second conductivity type; 11-Hole injection region; 12-Gate material layer. Detailed Implementation
[0019] The following specific examples illustrate the implementation of this application. Those skilled in the art can easily understand other advantages and effects of this application from the content disclosed in this specification. This application can also be implemented or applied through other different specific embodiments. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this application. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.
[0020] It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of this application. The drawings only show the components related to this application and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.
[0021] In the following description, numerous details are explored to provide a more thorough explanation of embodiments of the present application. However, it will be apparent to those skilled in the art that embodiments of the present application may be practiced without these specific details. In other embodiments, well-known structures and devices are shown in block diagram form rather than in detail to avoid obscuring embodiments of the present application.
[0022] Please see Figure 1 , Figure 1 This is a schematic diagram of the structure of a reverse-conducting insulated-gate bipolar transistor provided in an embodiment of this application, as shown below. Figure 1 As shown, the reverse-conducting insulated-gate bipolar transistor includes: The collector structure, drift region 5, carrier storage region 6, base region 8, and emitter region 9 of the first conductivity type are stacked sequentially along a first direction, and the first trench and the second trench are distributed at intervals along a second direction, wherein the first direction is perpendicular to the second direction. Both the first trench and the second trench extend from the side of the first conductivity type emission region 9 away from the base region 8 into the drift region 5; Both the first trench and the second trench are provided with hole injection regions 11 on the side away from the drift region 5. The hole injection regions 11 are used to provide holes that move toward the collector structure when the reverse-conducting insulated gate bipolar transistor is turned on in reverse. The hole injection regions 11 are provided with gate structures on the side away from the drift region 5.
[0023] Understandably, by setting the aforementioned hole injection region 11 in the reverse-conducting insulated-gate bipolar transistor, holes that can move toward the collector structure can be provided when the reverse-conducting insulated-gate bipolar transistor turns on in reverse, that is, when the reverse-conducting insulated-gate bipolar transistor changes from the forward blocking state to the reverse turning-on state. This prompts the drift region 5 to recover from the depletion state as soon as possible, accelerates the reverse turning-on process, improves the reverse turning-on performance of the reverse-conducting insulated-gate bipolar transistor, and has low cost and strong feasibility.
[0024] It's understandable that the first direction is the growth direction of the reverse-conducting insulated-gate bipolar transistor, i.e., from bottom to top. The second direction is the lateral extension direction, perpendicular to the first direction.
[0025] In some embodiments, the collector structure includes a first conductivity type collector region 2 and a second conductivity type collector region 1, wherein a preset interval is provided between the first conductivity type collector region 2 and the second conductivity type collector region 1, and the first conductivity type and the second conductivity type are different; A second conductivity type buffer layer 4 is provided between the first conductivity type collector area 2 and the drift area 5, and a first conductivity type buffer layer 3 is provided between the second conductivity type collector area 1 and the drift area 5. The second conductivity type buffer layer 4 covers the first conductivity type collector area 2, and the first conductivity type buffer layer 3 covers the second conductivity type collector area 1. The doping concentration of the first conductivity type collector region 2 is greater than the doping concentration of the second conductivity type buffer layer 4, and the doping concentration of the second conductivity type collector region 1 is greater than the doping concentration of the first conductivity type buffer layer 3.
[0026] In some examples of this embodiment, the first conductivity type can be N-type and the second conductivity type can be P-type.
[0027] In some examples of this embodiment, the first conductivity type collector region 2 can be a heavily doped first conductivity type collector region 2. The second conductivity type collector region 1 can be a heavily doped second conductivity type collector region 1. The first conductivity type buffer layer 3 can be a highly doped first conductivity type buffer layer 3. The second conductivity type buffer layer 4 can be a highly doped second conductivity type buffer layer 4. It can be understood that the doping concentration corresponding to heavy doping > the doping concentration corresponding to high doping > the doping concentration corresponding to medium doping > the doping concentration corresponding to low doping.
[0028] In some embodiments, the drift region 5 is a second conductivity type drift region, and the doping concentration of the second conductivity type drift region is lower than the doping concentration of the first conductivity type buffer layer 3.
[0029] In some examples of this embodiment, the second conductivity type drift region may be a low-doped second conductivity type drift region.
[0030] In some embodiments, the carrier storage region 6 is a carrier storage region of a first conductivity type, wherein the doping concentration of the first conductivity type carrier storage region is greater than the doping concentration of the second conductivity type drift region and lower than the doping concentration of the first conductivity type buffer layer 3.
[0031] In some examples of this embodiment, the first conductivity type carrier storage region may be a medium-doped first conductivity type carrier storage region.
[0032] In some embodiments, the base region 8 is a second conductivity type base region, and the doping concentration of the second conductivity type base region is greater than the doping concentration of the first conductivity type carrier storage region and lower than the doping concentration of the first conductivity type collector region 2.
[0033] In some examples of this embodiment, the second conductivity type base region can be a highly doped second conductivity type base region.
[0034] In some embodiments, the reverse-conducting insulated gate bipolar transistor further includes a second conductivity type emitter region 10, which penetrates the first conductivity type emitter region 9 and the base region 8. The doping concentration of the first conductivity type emitter region 9 and the doping concentration of the second conductivity type emitter region 10 are both greater than the doping concentration of the second conductivity type buffer layer 4.
[0035] In some examples of this embodiment, the first conductivity type emitter region 9 can be a heavily doped first conductivity type emitter region. The second conductivity type emitter region 10 can be a heavily doped second conductivity type emitter region.
[0036] In some embodiments, the gate structure includes an insulating dielectric layer 7 and a gate material layer 12; In the first trench, the insulating dielectric layer 7 covers the inner sidewall of the first trench, and the gate material layer 12 fills the trench formed by the insulating dielectric layer 7. In the second trench, the insulating dielectric layer 7 covers the inner sidewall of the second trench, and the gate material layer 12 fills the trench formed by the insulating dielectric layer 7.
[0037] In some embodiments, the gate material layer 12 is deposited using polysilicon material, and the doping concentration of the gate material layer 12 is greater than the doping concentration of the second conductivity type buffer layer 4.
[0038] In some examples of this embodiment, the gate material layer 12 may be heavily doped with a first conductivity type polysilicon layer.
[0039] In some embodiments, the hole injection region 11 is a second conductivity type hole injection region, wherein the doping concentration of the second conductivity type hole injection region is greater than the doping concentration of the first conductivity type carrier storage region and less than the doping concentration of the first conductivity type collector region 2.
[0040] In some examples of this embodiment, the second conductivity type hole injection region can be a highly doped second conductivity type hole injection region.
[0041] In some embodiments, the second conductivity type hole injection region and the first conductivity type carrier storage region are not connected.
[0042] In some embodiments, when the reverse-conducting insulated-gate bipolar transistor is in a forward blocking state, the gate material layer 12 is grounded, and the drift region 5 is in a depleted state after being subjected to a high collector-emitter voltage; the reverse-conducting insulated-gate bipolar transistor refers to the reverse-conducting insulated-gate bipolar transistor changing from a forward blocking state to a reverse-on state.
[0043] Understandably, by designing the above-mentioned reverse-conducting insulated-gate bipolar transistor, the reverse turn-on speed of the reverse-conducting insulated-gate bipolar transistor can be effectively accelerated, and the cost is relatively low.
[0044] Figure 2 The reverse turn-on curve of the reverse-conducting insulated-gate bipolar transistor provided in this application ( Figure 2 The curve corresponding to the "proposed technology" in the text) and the reverse turn-on curve of the reverse-conducting insulated-gate bipolar transistor in the prior art ( Figure 2 Please refer to the comparison chart (the curve corresponding to "existing technology") for details. Figure 2 The reverse turn-on speed of the reverse-conducting insulated-gate bipolar transistor provided in this application is faster than that of the reverse-conducting insulated-gate bipolar transistor in the prior art. Figure 2 The three coordinate axes are the emitter current coordinate axis (unit: A / cm). 2 (Amperes per square centimeter), time (μs), and emitter-collector voltage (V).
[0045] The above embodiments are merely illustrative of the principles and effects of this application and are not intended to limit this application. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of this application. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in this application should still be covered by the claims of this application.
Claims
1. A reverse-conducting insulated-gate bipolar transistor, characterized in that, include: The collector structure, drift region, carrier storage region, base region, and emitter region of first conductivity type are stacked sequentially along a first direction, and the first trench and the second trench are spaced apart along a second direction, wherein the first direction is perpendicular to the second direction; Both the first trench and the second trench extend from the side of the first conductivity type emitter region away from the base region into the drift region; Both the first trench and the second trench have hole injection regions on the side away from the drift region. The hole injection regions are used to provide holes that move toward the collector structure when the reverse-conducting insulated gate bipolar transistor is turned on in reverse. A gate structure is provided on the side of the hole injection region away from the drift region.
2. The reverse-conducting insulated-gate bipolar transistor according to claim 1, characterized in that, The collector structure includes a first conductivity type collector region and a second conductivity type collector region, with a preset interval between the first conductivity type collector region and the second conductivity type collector region, and the first conductivity type and the second conductivity type are different; A second conductivity type buffer layer is provided between the first conductivity type collector area and the drift area, and a first conductivity type buffer layer is provided between the second conductivity type collector area and the drift area. The second conductivity type buffer layer covers the first conductivity type collector area, and the first conductivity type buffer layer covers the second conductivity type collector area. The doping concentration of the first conductivity type collector region is greater than the doping concentration of the second conductivity type buffer layer, and the doping concentration of the second conductivity type collector region is greater than the doping concentration of the first conductivity type buffer layer.
3. The reverse-conducting insulated-gate bipolar transistor according to claim 2, characterized in that, The drift region is a second conductivity type drift region, and the doping concentration of the second conductivity type drift region is lower than the doping concentration of the first conductivity type buffer layer.
4. The reverse-conducting insulated-gate bipolar transistor according to claim 3, characterized in that, The carrier storage region is a first conductivity type carrier storage region, and the doping concentration of the first conductivity type carrier storage region is greater than the doping concentration of the second conductivity type drift region, but lower than the doping concentration of the first conductivity type buffer layer.
5. The reverse-conducting insulated-gate bipolar transistor according to claim 4, characterized in that, The base region is a second conductivity type base region, and the doping concentration of the second conductivity type base region is greater than the doping concentration of the first conductivity type carrier storage region and lower than the doping concentration of the first conductivity type collector region.
6. The reverse-conducting insulated-gate bipolar transistor according to claim 2, characterized in that, The reverse-conducting insulated gate bipolar transistor further includes a second conductivity type emitter region, which penetrates the first conductivity type emitter region and the base region. The doping concentration of both the first conductivity type emitter region and the second conductivity type emitter region is greater than the doping concentration of the second conductivity type buffer layer.
7. The reverse-conducting insulated-gate bipolar transistor according to claim 2, characterized in that, The gate structure includes an insulating dielectric layer and a gate material layer; In the first trench, the insulating dielectric layer covers the inner sidewall of the first trench, and the gate material layer fills the trench formed by the insulating dielectric layer; In the second trench, the insulating dielectric layer covers the inner sidewall of the second trench, and the gate material layer fills the trench formed by the insulating dielectric layer.
8. The reverse-conducting insulated-gate bipolar transistor according to claim 7, characterized in that, The gate material layer is deposited using polycrystalline silicon material, and the doping concentration of the gate material layer is greater than that of the second conductivity type buffer layer.
9. The reverse-conducting insulated-gate bipolar transistor according to claim 4, characterized in that, The hole injection region is a second conductivity type hole injection region. The doping concentration of the second conductivity type hole injection region is greater than the doping concentration of the first conductivity type carrier storage region and less than the doping concentration of the first conductivity type collector region.
10. The reverse-conducting insulated-gate bipolar transistor according to claim 7, characterized in that, When the reverse-conducting insulated-gate bipolar transistor is in the forward blocking state, the gate material layer is grounded and the drift region is in the depletion state; the reverse-conducting insulated-gate bipolar transistor refers to the reverse-conducting insulated-gate bipolar transistor changing from the forward blocking state to the reverse-on state.