Novel structure reverse conducting IGBT device capable of realizing high-frequency application and low dynamic loss
By setting up IGBT and FRD areas separately in the inverse guide IGBT devices and adding local life control areas to the IGBT areas, the parasitic inductance and tailing current problems in traditional inverse guide IGBT devices are solved, and the effects of high frequency applications and low dynamic losses are achieved.
Patent Information
- Application Number
- CN202421609226.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-09
- Publication Date
- 2025-05-16
- Estimated Expiration
- 2034-07-09
AI Technical Summary
Traditional inverse guide IGBT devices cannot be used at high frequency due to the increase in parasitic inductance and system volume due to the IGBT and FRD combination, and there is a long tailing current during the shutdown process, resulting in slow response speed, additional loss and heat increase.
A new structural inverse guide IGBT device is designed. By setting up separately between the IGBT region and the FRD region, the collector and emitter are shared, the chip area and volume are reduced, and a local life control area is added to the IGBT region. By introducing energy level traps to form a trap layer, the life of carriers is shortened.
High frequency applications and low dynamic losses of IGBT devices are realized, and the reliability and performance of the device are improved by reducing tailing current, improving shutdown speed, reducing losses and heat.
Smart Images
Figure CN222885079U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of RC-IGBT devices, and in particular to a novel structure reverse-conducting IGBT device for realizing high-frequency application with low dynamic loss. Background Art
[0002] IGBT (Insulated Gate Bipolar Transistor) is a composite voltage control device composed of MOS (insulated gate field effect transistor) and BJT (bipolar junction transistor), and is one of the mainstream power devices at present. Usually, IGBT needs to be connected in parallel with an FRD (fast recovery diode) for freewheeling protection in practical applications, thus forming a reverse-conducting IGBT device (RC-IGBT device). At present, the traditional reverse-conducting IGBT device needs to seal the IGBT and FRD together, which will increase the parasitic inductance and system volume, thereby affecting the reliability. In addition, in the application and testing of the traditional reverse-conducting IGBT device, it is found that the RC-IGBT device has a long tail current inside during the shutdown process, which leads to a slow shutdown response speed and a slow switching frequency, thereby affecting the high-frequency application of this reverse-conducting IGBT device. In addition, due to the existence of a long tail current, it will also cause additional loss increase, additional heat increase and other problems.
[0003] In view of this, how to solve the problems of traditional reverse-conducting IGBT devices, such as increased parasitic inductance and system volume, and inability to be used at high frequencies, has become a topic to be studied and solved by the present invention. Utility Model Content
[0004] The purpose of the utility model is to provide a reverse conducting IGBT device with a new structure that can achieve low dynamic losses in high-frequency applications. The purpose is to solve the problems of traditional reverse conducting IGBT devices that will lead to increased parasitic inductance and system volume, and cannot be used in high-frequency applications, so as to optimize the high-frequency performance of the reverse conducting IGBT device and thus achieve high-frequency application of the reverse conducting IGBT device.
[0005] To achieve the above-mentioned purpose, the technical solution adopted by the utility model is: to propose a new structure reverse conducting IGBT device with low dynamic loss in high-frequency application, wherein the reverse conducting IGBT device includes a collector, an emitter, a gate structure, and an IGBT region and an FRD region separately arranged between the collector and the emitter.
[0006] The IGBT regions are, from bottom to top, a P+ base region, a local lifetime control region, an N-Drift region, and a P well region.
[0007] The FRD region is composed of an N+ base region, an N-Drift region, and a P-well region from bottom to top.
[0008] The P+ base region and the N+ base region are located at the same level, and the N-Drift region and the P-well region in the IGBT region and the FRD region are located at the same level.
[0009] The local lifetime control region of the IGBT region is located on one side of the N-Drift region close to the P+ base region. The local lifetime control region has a trap layer, and the inner side of the trap layer is at a distance D from the vertical boundary between the FRD region and the IGBT region.
[0010] The multiple gate structures enter the N-Drift region from the P-well region of the IGBT region and the FRD region, and an N+ source region is arranged at the upper end of the gate structure located in the IGBT region, and an interlayer dielectric is arranged at the top of the gate structure located in the IGBT region and the top of the gate structure located in the FRD region.
[0011] The relevant contents of this utility model are explained as follows:
[0012] 1. The implementation of the above technical solution of the utility model, in view of the problems that the traditional reverse-conducting IGBT device will cause the increase of parasitic inductance and system volume, and cannot be used at high frequency, proposes a new structure reverse-conducting IGBT device that realizes low dynamic loss in high-frequency application. In this technical solution, by partitioning the IGBT area and the FRD area in a reverse-conducting IGBT device, the collector and emitter can be shared, the total area and volume of the chip are reduced, and the reliability is improved; and a local life control area is added to the IGBT area, and the local life control area is doped by introducing energy level traps to form a trap layer locally, shortening the life of minority carriers in the area. The advantage of this structure is that it can reduce the tail current during the shutdown process of the IGBT device, thereby achieving a higher shutdown speed, so that the new structure reverse-conducting IGBT device has the characteristics of high-frequency application. At the same time, because the tail current is very short, the device is prevented from generating additional heat, thereby reducing the loss, so that the new structure reverse-conducting IGBT device has the characteristics of low dynamic loss.
[0013] 2. In the above technical solution, the collector electrode is made of titanium-nickel-silver alloy, so that the RC-IGBT device has better corrosion resistance, heat resistance and stability, and the device can be used stably and has a long service life.
[0014] 3. In the above technical solution, the emitter material is aluminum-silicon-copper alloy, so as to reduce the cost of the emitter of the RC-IGBT device while ensuring that the RC-IGBT device has good thermal conductivity, stability and strength.
[0015] 4. In the above technical solution, the gate structure is composed of gate polysilicon and a silicon dioxide layer located on the outer layer of the gate polysilicon. This design is used to improve the short-circuit withstand and withstand voltage characteristics of the device, while reducing the surge voltage and switching loss of the device during the switching process.
[0016] 5. In the above technical solution, the distance between the P-well region / N-Drift junction and the upper surface of the trap layer is D1, and the distance between the P+ base region / N-Drift junction and the lower surface of the trap layer is D2, wherein D1>>D2, the benefits of D1>>D2 are: improving the comprehensive performance of RC-IGBT, increasing the carrier concentration on the emitter side to reduce the saturation voltage drop, and reducing the carrier concentration on the collector side to speed up the turn-off speed and reduce the turn-off loss.
[0017] 6. In the above technical solution, the length ratio of the P+ base region to the N+ base region is 3:2. The effect of the effective length ratio is: the extra length of the P+ base region increases the resistance of the region, the voltage drop of the P+ base region / N-Drift is improved, and the RC-IGBT device switches from unipolar conduction to bipolar conduction faster, suppressing the Snapback effect, and the sufficient length of the N+ base region will not affect the reverse conduction capability.
[0018] 7. In the above technical solution, the number of gate structures in the IGBT region and the FRD region is three each.
[0019] 8. In the above technical solution, the local lifetime control region is formed by light ion (H, He) irradiation to form the local lifetime control region and high temperature annealing activation.
[0020] 9. In this utility model, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.
[0021] 10. In the present utility model, the orientation or position relationship indicated by the terms "center", "upper", "lower", "axial", "bottom", "inner", "outer", etc. is based on the orientation or position assembly relationship shown in the drawings, which is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application.
[0022] 11. In addition, the terms "first", "second", etc. are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of this application, "plurality" means at least two, such as two, three, etc., unless otherwise clearly and specifically defined.
[0023] Due to the application of the above technical solution, the utility model has the following advantages compared with the prior art:
[0024] The utility model aims at the problems of traditional reverse conducting IGBT devices, such as increased parasitic inductance and system volume, and inability to be used at high frequencies, and proposes a reverse conducting IGBT device with a novel structure that can achieve low dynamic loss in high frequency applications. In this technical solution, by partitioning the IGBT region and the FRD region in a reverse conducting IGBT device, the collector and emitter can be shared, thereby reducing the total area and volume of the chip and improving reliability; and a local lifetime control region is added to the IGBT region. When the device turns from on to off, the local lifetime control region is doped by introducing energy level traps to locally form a trap layer, thereby shortening the lifetime of minority carriers in the region. The advantage of this structure is that it can reduce the tail current during the shutdown process of the IGBT device, thereby achieving a higher shutdown speed, so that the reverse conducting IGBT device with the novel structure has the characteristics of high frequency application. At the same time, because the tail current is very short, the device is prevented from generating additional heat, thereby reducing the loss, so that the reverse conducting IGBT device with the novel structure has the characteristics of low dynamic loss. BRIEF DESCRIPTION OF THE DRAWINGS
[0025] Figure 1 A schematic diagram of a novel structure reverse-conducting IGBT device for realizing low dynamic loss in high-frequency applications according to an embodiment of the utility model;
[0026] Figure 2 It is a schematic diagram of the IGBT region in an embodiment of the present utility model.
[0027] In the above attached figure:
[0028] 100. IGBT area
[0029] 200, FRD area
[0030] 1. Collector
[0031] 21. P+ base region
[0032] 22. N+ base region
[0033] 3. N-Drift Zone
[0034] 4. P-well region
[0035] 5. Emitter
[0036] 6. Local life control area
[0037] 61. Trap Layer
[0038] 7. Gate structure
[0039] 71. Gate polysilicon
[0040] 72. Silicon dioxide layer
[0041] 8. N+ source region
[0042] 9. Interlayer dielectric
[0043] 10. Emitter. DETAILED DESCRIPTION
[0044] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present application, so the present application is not limited by the specific embodiments disclosed below.
[0045] The utility model aims to solve the problems that the traditional reverse-conducting IGBT device needs to seal the IGBT together with the FRD, which will increase the parasitic inductance and system volume, thereby affecting the reliability, and the RC-IGBT device has a long tail current inside during the shutdown process, which leads to slow shutdown response speed, slow switching frequency, and also causes additional loss increase, additional heat increase, etc.
[0046] The embodiment of the utility model proposes a novel structure reverse-conducting IGBT device that realizes low dynamic loss in high-frequency applications, such as Figure 1 , Figure 2 As shown, the reverse conducting IGBT device includes a collector 1 , an emitter 510 , a gate structure 7 , and an IGBT region 100 and an FRD region 200 separately disposed between the collector 1 and the emitter 510 .
[0047] The IGBT region 100 includes, from bottom to top, a P+ base region 21 , a local lifetime control region 6 , an N-Drift region 3 , and a P well region 4 .
[0048] The FRD region 200 includes an N+ base region 22 , an N-Drift region 3 , and a P-well region 4 from bottom to top.
[0049] The P+ base region 21 and the N+ base region 22 are located at the same level, and the N-Drift region 3 and the P-well region 4 in the IGBT region 100 and the FRD region 200 are located at the same level.
[0050] The local lifetime control region 6 of the IGBT region 100 is located on one side of the N-Drift region 3 close to the P+ base region 21. The local lifetime control region 6 has a trap layer 61, and the inner side of the trap layer 61 has a distance D from the vertical dividing line between the FRD region 200 and the IGBT region 100.
[0051] The multiple gate structures 7 enter the N-Drift region 3 from the P-well region 4 of the IGBT region 100 and the FRD region 200, and an N+ source region 8 is arranged at the upper end of the gate structure 7 located in the IGBT region 100, and an interlayer dielectric 9 is arranged at the top of the gate structure 7 located in the IGBT region 100 and the top of the gate structure 7 located in the FRD region 200.
[0052] Through the implementation of the embodiment of the utility model, by partitioning the IGBT region 100 and the FRD region 200 in a reverse-conducting IGBT device, the collector 1 and the emitter 510 can be shared, thereby reducing the total area and volume of the chip and improving reliability; and a local lifetime control region 6 is added to the IGBT region 100, and the local lifetime control region 6 is doped by introducing energy level traps to locally form a trap layer 61, thereby shortening the life of minority carriers in the region. The advantage of this structure is that it can reduce the tail current during the shutdown process of the IGBT device, thereby achieving a higher shutdown speed, so that the new structure reverse-conducting IGBT device has the characteristics of high-frequency application, and at the same time, because the tail current is very short, the device is prevented from generating additional heat, thereby reducing the loss, so that the new structure reverse-conducting IGBT device has the characteristics of low dynamic loss.
[0053] In the embodiment of the utility model, the material of the collector 1 is a titanium-nickel-silver alloy. This allows the RC-IGBT device to have better corrosion resistance, heat resistance, and stability, allowing the device to be used stably and have a long life. The material of the emitter 510 is an aluminum-silicon-copper alloy. This allows the RC-IGBT device to have good thermal conductivity, stability, and strength, while reducing the cost of the emitter 510 of the RC-IGBT device.
[0054] In the embodiment of the utility model, the gate structure 7 is composed of a gate polysilicon 71 and a silicon dioxide layer 72 located on the outer layer of the gate polysilicon 71. This design improves the short circuit withstand and withstand voltage characteristics of the device, while reducing the surge voltage and switching loss of the device during the switching process.
[0055] In the embodiment of the present utility model, Figure 2 As shown, the distance between the junction of the P-well region 4 / N-Drift and the upper surface of the trap layer 61 is D1, and the distance between the junction of the P+ base region 21 / N-Drift and the lower surface of the trap layer 61 is D2, wherein D1>>D2, the benefits of D1>>D2 are: improving the comprehensive performance of the RC-IGBT, increasing the carrier concentration on the emitter 510 side to reduce the saturation voltage drop, and reducing the carrier concentration on the collector 1 side to speed up the turn-off speed and reduce the turn-off loss.
[0056] In the embodiment of the utility model, the length ratio of the P+ base region 21 to the N+ base region 22 is 3:2. The effect of the effective length ratio is: the extra length of the P+ base region 21 increases the resistance of this region, the voltage drop of the P+ base region 21 / N-Drift is improved, and the RC-IGBT device switches from unipolar conduction to bipolar conduction faster, suppressing the Snapback effect, and the sufficient length of the N+ base region 22 will not affect the reverse conduction capability.
[0057] In the embodiment of the present invention, the local lifetime control region 6 is formed by light ion (H, He) irradiation to form the local lifetime control region 6 and high temperature annealing activation, thereby locally forming a trap layer 61.
[0058] In addition, the technical solution of the utility model is introduced with one of the detailed embodiments.
[0059] In this detailed embodiment, a novel structure reverse-conducting IGBT device for realizing low dynamic loss in high-frequency application is proposed, including a collector 1, an emitter 510, and a gate structure 7. The material of the collector 1 is a titanium-nickel-silver alloy, the material of the emitter 510 is an aluminum-silicon-copper alloy, and the gate structure 7 is composed of a gate polysilicon 71 and a silicon dioxide layer 72 located on the outer layer of the gate polysilicon 71. An IGBT region 100 and an FRD region 200 are separately provided between the collector 1 and the emitter 510.
[0060] In this detailed embodiment, the IGBT region 100 is composed of a P+ base region 21, a local lifetime control region 6, an N-Drift region 3, and a P-well region 4 from bottom to top; the FRD region 200 is composed of an N+ base region 22, an N-Drift region 3, and a P-well region 4 from bottom to top; wherein the P+ base region 21 and the N+ base region 22 are located at the same level, and the N-Drift region 3 and the P-well region 4 in the IGBT region 100 and the FRD region 200 are located at the same level; the plurality of gate structures 7 enter the N-Drift region 3 from the P-well region 4 of the IGBT region 100 and the FRD region 200, and an N+ source region 8 is provided at the upper end of the gate structure 7 located in the IGBT region 100, and an interlayer dielectric 9 is provided at the top of the gate structure 7 located in the IGBT region 100 and the top of the gate structure 7 located in the FRD region 200.
[0061] In this detailed embodiment, the local lifetime control region 6 of the IGBT region 100 is located on one side of the N-Drift region 3 close to the P+ base region 21, and the local lifetime control region 6 has a trap layer 61, and the inner side of the trap layer 61 has a distance D from the vertical boundary between the FRD region 200 and the IGBT region 100; the distance between the P-well region 4 / N-Drift junction and the upper surface of the trap layer 61 is D1, and the distance between the P+ base region 21 / N-Drift junction and the lower surface of the trap layer 61 is D2, wherein D1>>D2, for example, D1 can be 3 to 10 times of D2. The length ratio of the P+ base region 21 to the N+ base region 22 is 3:2.
[0062] The above embodiments are only for illustrating the technical concept and features of the utility model, and their purpose is to enable people familiar with the technology to understand the content of the utility model and implement it accordingly, and they cannot be used to limit the protection scope of the utility model. Any equivalent changes or modifications made according to the spirit of the utility model should be included in the protection scope of the utility model.
Claims
1. A novel reverse-conducting IGBT device with a high-frequency application and low dynamic loss, characterized in that: The reverse conducting IGBT device comprises a collector, an emitter, a gate structure, and an IGBT region and an FRD region separately arranged between the collector and the emitter; The IGBT regions are, from bottom to top, a P+ base region, a local lifetime control region, an N-Drift region, and a P well region; The FRD region is composed of an N+ base region, an N-Drift region, and a P-well region from bottom to top; The P+ base region and the N+ base region are located at the same level, and the N-Drift region and the P-well region in the IGBT region and the FRD region are located at the same level; The local lifetime control region of the IGBT region is located on one side of the N-Drift region close to the P+ base region, the local lifetime control region has a trap layer, and the inner side of the trap layer is at a distance D from a vertical boundary line between the FRD region and the IGBT region; The multiple gate structures enter the N-Drift region from the P-well region of the IGBT region and the FRD region, and an N+ source region is arranged at the upper end of the gate structure located in the IGBT region, and an interlayer dielectric is arranged at the top of the gate structure located in the IGBT region and the top of the gate structure located in the FRD region.
2. According to claim 1, a novel structure reverse conducting IGBT device for realizing high frequency application and low dynamic loss, characterized in that: The material of the collector is titanium-nickel-silver alloy.
3. The novel reverse-conducting IGBT device with a high-frequency application and low dynamic loss according to claim 1, characterized in that: The material of the emitter is aluminum-silicon-copper alloy.
4. The novel reverse-conducting IGBT device for realizing high-frequency application and low dynamic loss according to claim 1, characterized in that: The gate structure is composed of gate polysilicon and a silicon dioxide layer located outside the gate polysilicon.
5. The novel reverse-conducting IGBT device for realizing high-frequency application and low dynamic loss according to claim 1, characterized in that: The distance between the P-well region / N-Drift interface and the upper surface of the trap layer is D1, and the distance between the P+ base region / N-Drift interface and the lower surface of the trap layer is D2, wherein D1>>D2.
6. The novel reverse-conducting IGBT device with a high-frequency application and low dynamic loss according to claim 1, characterized in that: The length ratio of the P+ base region to the N+ base region is 3:
2.
7. The novel reverse-conducting IGBT device for realizing high-frequency application and low dynamic loss according to claim 1, characterized in that: The number of gate structures in the IGBT region and the number of gate structures in the FRD region are three respectively.
8. The novel reverse-conducting IGBT device for realizing high-frequency application and low dynamic loss according to claim 1, characterized in that: The local lifetime control region is formed by light ion irradiation to form the local lifetime control region and high temperature annealing activation.