Reverse conducting RC-IGBT device

Abstract

The invention discloses a reverse conducting RC-IGBT (Reverse Conducting-Insulated Gate Bipolar Translator) device, which relates to the technical field of semiconductors, reduces a voltage turn-back phenomenon, improves the stability, the reliability, the voltage endurance capability and the switching speed of the device, and reduces the switching loss. By arranging the P + buffer layer and the field limiting ring structure, the thermal management performance and the voltage endurance capability of the device are improved, and the service life of the device is prolonged; and a composite buffer structure is formed, so that the conduction voltage drop and the switching loss of the device are reduced. According to the scheme, the IGBT device comprises a semiconductor substrate and an IGBT device main body formed on the semiconductor substrate, the IGBT device main body is composed of an emitter, a grid, a collector and a field limiting ring structure; the emitter region comprises a P + type emitter region and an N type base region; the emitter region further comprises an N + heavily doped region and an N-lightly doped region to form a composite buffer structure; the gate region comprises a gate oxide layer and a polycrystalline silicon filling layer; the collector region comprises an N + doped region and a P + buffer layer, and the N + doped region forms a PIN diode structure and is reversely connected with the IGBT device in parallel.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor technology, and in particular to a reverse conducting RC-IGBT device. Background Art

[0002] An insulated gate bipolar transistor (IGBT) is a power device that combines a metal oxide semiconductor field effect transistor and a bipolar junction transistor. It has the advantages of high input impedance and low on-state voltage drop and is widely used as a high-voltage switch.

[0003] Existing RC-IGBT devices have voltage foldback during forward conduction, and in high-frequency switching applications, their switching loss and thermal management performance still need to be further optimized. Voltage foldback refers to the fact that in the early stage of forward conduction, the P-emitter region cannot inject holes into the N-drift region, resulting in no conductivity modulation effect in the N-drift region, making the on-resistance very large and the voltage folding back. This phenomenon affects the stability and reliability of the device and limits its use in high-frequency applications.

[0004] In order to solve the above problems, many researchers have proposed various improvement schemes: for example, by increasing the short-circuit resistance of the device collector region, reducing the resistance of the device drift region, or introducing a new structure to change the reverse conduction mode, to reduce the voltage foldback phenomenon. However, these methods usually make the device structure complicated, have high requirements on the process, and may have an adverse effect on certain characteristics of the device (such as reverse recovery characteristics, blocking characteristics, etc.). Summary of the invention

[0005] The present invention provides a reverse-conducting RC-IGBT device, which reduces voltage foldback and improves device stability and reliability by optimizing the thickness and doping concentration of an N+ doping region; adopts a trench gate structure to improve the withstand voltage and switching speed of the device and reduce switching losses; provides a P+ buffer layer and a field limiting ring structure to improve the thermal management performance and withstand voltage of the device and extend the service life of the device; forms a composite buffer structure in the emitter region to reduce the on-state voltage drop and switching losses of the device.

[0006] In order to achieve the above object, the present invention adopts the following technical scheme: The present invention provides a reverse conducting RC-IGBT device, comprising: A semiconductor substrate and an IGBT device body formed on the semiconductor substrate.

[0007] The IGBT device body is composed of an emitter, a gate, a collector and a field limiting ring structure; the emitter region includes a P+ type emitter region and an N type base region; the emitter region also includes an N+ heavily doped region and an N- lightly doped region to form a composite buffer structure; the gate region includes a gate oxide layer and a polysilicon filling layer; the collector region includes an N+ doped region and a P+ buffer layer, and the N+ doped region forms a PIN diode structure and is reversely connected in parallel with the IGBT device.

[0008] Furthermore, in the reverse conducting RC-IGBT device, the IGBT device body further includes: a drift region.

[0009] The drift region adopts a non-planar structure, and the non-planar structure has an arc-shaped transition area; the curvature radius of the non-planar structure is 50 microns-100 microns.

[0010] Furthermore, in the reverse conducting RC-IGBT device, the drift region comprises:

[0011] The thickness of the drift region is 40 microns to 120 microns; the doping concentration of the drift region is for .

[0012] Furthermore, in the reverse-conducting RC-IGBT device, the composite buffer structure comprises: The thickness of the N+ heavily doped region in the composite buffer structure is 1 micron to 1.5 microns; the doping concentration of the N+ heavily doped region is The thickness of the N-lightly doped region in the composite buffer structure is 4 microns to 6 microns, and the doping concentration of the N-lightly doped region is .

[0013] Furthermore, in the reverse-conducting RC-IGBT device, the gate comprises: The length of the gate is 8 micrometers to 12 micrometers; the spacing between the gates is 4 micrometers to 6 micrometers.

[0014] Furthermore, in the reverse conducting RC-IGBT device, the gate further comprises: The gate adopts a trench gate structure; the thickness of the gate oxide layer is 50 nanometers to 100 nanometers.

[0015] Furthermore, in the reverse conducting RC-IGBT device, the trench gate structure comprises: The depth of the groove gate structure is 2 micrometers to 5 micrometers; the width of the groove gate structure is 0.5 micrometers to 2 micrometers.

[0016] Furthermore, in the reverse conducting RC-IGBT device, the N+ doped region comprises: The doping concentration of the N+ doping region is ; The junction depth of the N+ doped region is 2 microns to 5 microns.

[0017] Furthermore, in the reverse conducting RC-IGBT device, the P+ buffer layer comprises: The thickness of the P+ buffer layer is 1 micron to 5 microns; the doping concentration of the P+ buffer layer is .

[0018] Furthermore, in the reverse conducting RC-IGBT device, the field limiting ring structure comprises: The width of the field limiting ring structure is 3 microns to 10 microns.

[0019] The invention provides a reverse-conducting RC-IGBT device, comprising: a semiconductor substrate and an IGBT device body formed on the semiconductor substrate; the IGBT device body consists of an emitter, a gate, a collector and a field-limiting ring structure; the emitter region comprises a P+ type emitter region and an N type base region; the emitter region further comprises an N+ heavily doped region and an N- lightly doped region to form a composite buffer structure; the gate region comprises a gate oxide layer and a polysilicon filling layer; the collector region comprises an N+ doped region and a P+ buffer layer, the N+ doped region forms a PIN diode structure and is reversely connected in parallel with the IGBT device. Compared with the prior art, the invention reduces the voltage foldback phenomenon and improves the stability and reliability of the device by optimizing the thickness and doping concentration of the N+ doped region; adopts a trench gate structure to improve the withstand voltage and switching speed of the device and reduce the switching loss; by arranging the P+ buffer layer and the field-limiting ring structure, the thermal management performance and withstand voltage of the device are improved and the service life of the device is extended; a composite buffer structure is formed in the emitter region to reduce the on-state voltage drop and switching loss of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. The drawings are only used to illustrate the implementation methods and are not to be considered as limitations of the present invention.

[0021] Figure 1 It is a schematic diagram of the structure of the reverse-conducting RC-IGBT device in Embodiment 1 of the present invention; Figure 2 It is a schematic diagram of the structure of the reverse-conducting RC-IGBT device in Embodiment 2 of the present invention; In the figure: 1. semiconductor substrate; 2. IGBT device body; 21. emitter; 22. gate; 23. collector; 24. field limiting ring structure; 211. P+ type emitter region; 212. N-type base region; 213. N+ heavily doped region; 214. N- lightly doped region; 221. gate oxide layer; 222. polysilicon filling layer; 231. N+ doped region; 232. P+ buffer layer; 25. drift region. DETAILED DESCRIPTION

[0022] The technical scheme in the embodiment of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiment of the present invention. Obviously, the described embodiment is only a part of the embodiment of the present invention, not all of the embodiments. Based on the embodiment of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0023] Unless otherwise defined, all technical and scientific terms used in the present invention have the same meaning as commonly understood by technicians in the field of the present invention; the terms used in the present invention are only for the purpose of describing specific embodiments, and are not intended to limit the terms "including" and "having" and any variations thereof in the specification and claims of the present invention and the above-mentioned drawings, and are intended to cover non-exclusive inclusions.

[0024] In the description of the embodiments of the present invention, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present invention, the meaning of "multiple" is more than two, unless otherwise clearly and specifically defined.

[0025] In the description of the embodiments of the present invention, the term "and / or" is only a description of the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B may represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0026] In the description of the embodiments of the present invention, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0027] In the description of the embodiments of the present invention, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the embodiments of the present invention.

[0028] In the description of the embodiments of the present invention, unless otherwise clearly specified and limited, technical terms such as "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 or an electrical connection; it can be 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. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of the present invention can be understood according to the specific circumstances.

[0029] Embodiment 1

[0030] The embodiment of the present invention provides a reverse conducting RC-IGBT device, such as Figure 1 As shown, including: A semiconductor substrate 1 and an IGBT device body 2 formed on the semiconductor substrate.

[0031] Among them, the semiconductor substrate 1 is the basic material for manufacturing semiconductor devices, and is used to support and construct various semiconductor devices. It is usually a thin piece of single crystal material with high crystalline integrity and electrical properties, providing the necessary physical and chemical basis for subsequent semiconductor process steps. Common materials for the semiconductor substrate 1 are silicon, gallium arsenide, silicon carbide, gallium nitride, etc.

[0032] IGBT device body 2 (Insulated Gate Bipolar Transistor, insulated gate bipolar transistor) is a composite fully controlled voltage-driven power semiconductor device that combines the characteristics of MOSFET (metal oxide semiconductor field effect transistor) and BJT (bipolar transistor). It has the advantages of MOSFET's high input impedance and fast switching characteristics and BJT's low on-state voltage drop, and is widely used in various power electronic equipment.

[0033] The IGBT device body 2 is composed of an emitter 21, a gate 22, a collector 23 and a field limiting ring structure 24; the emitter 21 region includes a P+ type emitter region 211 and an N type base region 212; the emitter 21 region also includes an N+ heavily doped region 213 and an N- lightly doped region 214 to form a composite buffer structure; the gate 22 region includes a gate oxide layer 221 and a polysilicon filling layer 222; the collector 23 region includes an N+ doped region 231 and a P+ buffer layer 232, and the N+ doped region 231 forms a PIN diode structure and is reversely connected in parallel with the IGBT device.

[0034] The emitter 21 is an important region in the IGBT device body 2 , which is mainly responsible for emitting carriers (electrons or holes) to form a current path, thereby realizing the on and off functions of the IGBT device body 2 .

[0035] The P+ type emitter region 211 is used to form a low-resistance emitter contact to ensure that current can flow efficiently from the emitter to the base region.

[0036] The N-type base region 212 is used to form the source region of the MOSFET, and cooperates with the P+-type emitter region 211 to participate in the on and off control of the IGBT device body 2 .

[0037] The N+ heavily doped region 213 refers to a region formed in a semiconductor material by doping N-type impurities (such as phosphorus or arsenic) at a high concentration.

[0038] The N-lightly doped region 214 refers to a region formed in a semiconductor material by doping N-type impurities (such as phosphorus or arsenic) at a low concentration.

[0039] The gate 22 is a key part for controlling the on and off of the IGBT device body 2. The gate 22 controls the formation and closing of the MOSFET channel by applying voltage, thereby realizing the control of the on state of the IGBT. The design and structure of the gate 22 have an important influence on the switching speed, driving voltage and power consumption of the IGBT device body 2.

[0040] The gate oxide layer 221 is located between the gate 22 and the semiconductor substrate 1 and is a dense dielectric layer, usually made of silicon dioxide (SiO2). The gate oxide layer 221 is used to provide insulation isolation to prevent the gate 22 from directly contacting the semiconductor substrate 1 and causing a short circuit, while controlling the flow of current.

[0041] The polysilicon filling layer 222 is a material layer commonly used in semiconductor device manufacturing and is used to fill trenches or serve as the material of the gate 22 .

[0042] The collector 23 is an important region of the IGBT device body 2, responsible for collecting and outputting current. The design and structure of the collector 23 have a significant impact on the performance of the IGBT, including the on-state voltage drop, withstand voltage capability and switching speed.

[0043] The N+ doping region 231 refers to a region formed by doping N-type impurities (such as phosphorus or arsenic) at a high concentration. The N+ doping region 231 is generally used to form a low resistance path, provide good electrical contact, reduce contact resistance, and improve the conduction efficiency of the IGBT device body 2.

[0044] The P+ buffer layer 232 refers to a region formed by doping P-type impurities (such as boron) at a high concentration. The P+ buffer layer 232 is generally used to improve the thermal management performance and reliability of the IGBT device body 2, reduce the heat accumulation of the IGBT device body 2 during high-power operation, and extend the service life of the IGBT device body 2.

[0045] The field limiting ring structure 24 is a key structural design for improving the withstand voltage performance of the IGBT device body 2 and reducing the electric field concentration effect. It optimizes the electric field distribution and improves the breakdown voltage and reliability of the IGBT device body 2 by forming one or more floating high-doped regions at the edge of the IGBT device body 2.

[0046] An embodiment of the present invention provides a reverse conducting RC-IGBT device, comprising: a semiconductor substrate and an IGBT device body formed on the semiconductor substrate; the IGBT device body is composed of an emitter, a gate, a collector and a field limiting ring structure; the emitter region comprises a P+ type emitter region and an N type base region; the emitter region further comprises an N+ heavily doped region and an N- lightly doped region to form a composite buffer structure; the gate region comprises a gate oxide layer and a polysilicon filling layer; the collector region comprises an N+ doped region and a P+ buffer layer, the N+ doped region forms a PIN diode structure, and is reversely connected in parallel with the IGBT device. Compared with the prior art, the embodiment of the present invention improves the thermal management performance and voltage resistance of the device and prolongs the service life of the device by setting a P+ buffer layer and a field limiting ring structure; a composite buffer structure is formed in the emitter region to reduce the on-state voltage drop and switching loss of the device.

[0047] Embodiment 2

[0048] The embodiment of the present invention provides a reverse conducting RC-IGBT device, such as Figure 2 As shown, including: A semiconductor substrate 1 and an IGBT device body 2 formed on the semiconductor substrate.

[0049] The IGBT device body 2 is composed of an emitter 21, a gate 22, a collector 23 and a field limiting ring structure 24; the emitter 21 region includes a P+ type emitter region 211 and an N type base region 212; the emitter 21 region also includes an N+ heavily doped region 213 and an N- lightly doped region 214 to form a composite buffer structure; the gate 22 region includes a gate oxide layer 221 and a polysilicon filling layer 222; the collector 23 region includes an N+ doped region 231 and a P+ buffer layer 232, and the N+ doped region 231 forms a PIN diode structure and is reversely connected in parallel with the IGBT device.

[0050] Preferably, in the reverse conducting RC-IGBT device, the IGBT device body 2 further includes: a drift region 25; The drift region 25 adopts a non-planar structure, and the non-planar structure has an arc-shaped transition region; the curvature radius of the non-planar structure is 50 micrometers to 100 micrometers.

[0051] The non-planar structure of the drift region 25 means that the shape of the drift region 25 is not a traditional planar structure, but has an arc-shaped transition area. This structural design can optimize the electric field distribution, reduce the electric field concentration phenomenon, and improve the voltage resistance and reliability of the device. The radius of curvature of the non-planar structure is usually between 50 microns and 100 microns, and the specific value depends on the design and application requirements of the IGBT device body 2.

[0052] Preferably, in the reverse conducting RC-IGBT device, the drift region 25 comprises: The thickness of the drift region 25 is 40 micrometers to 120 micrometers; the doping concentration of the drift region 25 is .

[0053] Among them, the setting of the thickness range of the drift region 25 is mainly based on the performance requirements of the IGBT device body 2. A thicker drift region 25 can withstand a higher voltage because the distribution of the electric field in the drift region 25 will change with the increase of thickness, while a thinner drift region 25 can reduce the on-resistance of the IGBT device body 2, which is beneficial to reduce the conduction loss of the IGBT device body 2 in low-voltage, high-current application scenarios.

[0054] Preferably, the reverse-conducting RC-IGBT device, the composite buffer structure comprises: The thickness of the N+ heavily doped region 213 in the composite buffer structure is 1 micron to 1.5 microns; the doping concentration of the N+ heavily doped region 213 is The thickness of the N-lightly doped region 214 in the composite buffer structure is 4 microns to 6 microns, and the doping concentration of the N-lightly doped region 214 is .

[0055] The thickness range of the N+ heavily doped region 213 is selected mainly to ensure good electrical contact and low resistance while avoiding other problems caused by excessive thickness. A thickness of 1 micron to 1.5 microns can ensure that there are enough doping atoms to provide a large number of carriers (electrons), thereby reducing contact resistance and improving the conductivity of the IGBT device body 2. A high doping concentration means that there are a large number of impurity atoms per unit volume, and these impurity atoms provide a large number of free electrons, thereby significantly reducing resistivity.

[0056] The thickness of the N-lightly doped region 214 is relatively thick, and is usually used to form a drift region or a buffer region. The thickness of 4 microns to 6 microns can provide sufficient space to disperse the electric field and improve the voltage resistance of the IGBT device body 2. The thicker N-lightly doped region 214 can effectively reduce the electric field strength and prevent the IGBT device body 2 from being broken down due to excessive electric field. Low doping concentration means fewer impurity atoms per unit volume, thereby providing a lower carrier concentration. This low doping concentration N-lightly doped region 214 can effectively improve the voltage resistance of the IGBT device body 2, because the lower carrier concentration can reduce the electric field strength and prevent the IGBT device body 2 from being broken down due to excessive electric field.

[0057] Preferably, in the reverse-conducting RC-IGBT device, the gate 22 comprises: The length of the gate 22 is 8 micrometers to 12 micrometers; the interval between the gates 22 is 4 micrometers to 6 micrometers.

[0058] Among them, the length of the gate 22 is an important parameter that affects the current control capability of the IGBT device body 2. A longer gate 22 can more effectively control the current in the channel and improve the switching ratio (i.e., the ratio of the on-state current to the off-state current) of the IGBT device body 2. A gate 22 length of 8 microns to 12 microns can provide better current control capability. The spacing of the gate 22 affects the integration density of the IGBT device body 2. A smaller gate spacing can increase the number of IGBT device bodies 2 per unit area, thereby improving the integration of the chip and reducing the cost of the IGBT device body 2.

[0059] Preferably, in the reverse conducting RC-IGBT device, the gate 22 further comprises: The gate 22 adopts a trench gate structure; the thickness of the gate oxide layer 221 is 50 nanometers to 100 nanometers.

[0060] The trench gate structure is a structure in which the gate 22 is embedded in a trench in the semiconductor substrate 1 to form a vertical channel. The thickness of the gate oxide layer 221 directly affects the electric field distribution of the IGBT device body 2. A thicker gate oxide layer 221 can better disperse the electric field and improve the withstand voltage capability of the device.

[0061] Preferably, in the reverse conducting RC-IGBT device, the trench gate structure comprises: The depth of the groove gate structure is 2 micrometers to 5 micrometers; the width of the groove gate structure is 0.5 micrometers to 2 micrometers.

[0062] Among them, the deeper trench gate structure can effectively disperse the electric field and improve the withstand voltage capability of the IGBT device body 2. In high voltage applications, the deep trench gate structure can reduce the electric field concentration phenomenon and reduce the risk of device breakdown. The narrower trench gate structure can significantly increase the number of IGBT device bodies 2 per unit area and improve the integration. The width of 0.5 microns to 2 microns can achieve high-density integration while ensuring the performance of the IGBT device body 2.

[0063] Preferably, in the reverse conducting RC-IGBT device, the N+ doped region 231 comprises: The doping concentration of the N+ doping region 231 is ; The junction depth of the N+ doped region 231 is 2 microns to 5 microns.

[0064] Among them, the high doping concentration of the N+ doping region 231 means that there are a large number of donor impurity atoms in a unit volume, and these impurity atoms provide a large number of free electrons, thereby significantly reducing the resistivity and improving the conductivity. The deeper junction depth can effectively disperse the electric field and improve the withstand voltage capability of the IGBT device body 2. In high voltage applications, the deep junction depth can reduce the electric field concentration phenomenon and reduce the risk of breakdown of the IGBT device body 2.

[0065] Preferably, in the reverse conducting RC-IGBT device, the P+ buffer layer 232 comprises: The thickness of the P+ buffer layer 232 is 1 micron to 5 microns; the doping concentration of the P+ buffer layer 232 is .

[0066] Among them, the thicker P+ buffer layer 232 can effectively disperse the electric field and improve the withstand voltage capability of the IGBT device body 2. In high voltage applications, the thick P+ buffer layer 232 can reduce the electric field concentration phenomenon and reduce the risk of breakdown of the IGBT device body 2. The high doping concentration of the P+ buffer layer 232 means that there are a large number of acceptor impurity atoms per unit volume, and these impurity atoms provide a large number of holes, thereby significantly reducing the resistivity and improving the conductivity.

[0067] Preferably, in the reverse conducting RC-IGBT device, the field limiting ring structure 24 comprises: The width of the field limiting ring structure 24 is 3 micrometers to 10 micrometers.

[0068] Among them, the main function of the field limiting ring structure 24 is to improve the withstand voltage of the IGBT device body 2. The wider field limiting ring structure 24 can disperse the electric field more effectively, reduce the electric field concentration phenomenon, and thus improve the breakdown voltage of the IGBT device body 2. The field limiting ring structure 24 forms equipotential lines on the surface of the IGBT device body 2, thereby reducing the intensity of the surface electric field and preventing surface breakdown. A width of 3 microns to 10 microns can form a sufficiently wide equipotential area on the surface of the IGBT device body 2, effectively reducing the surface electric field.

[0069] It should be noted here that the detailed description of each component of this embodiment can refer to other embodiments and will not be repeated here.

[0070] The invention provides a reverse-conducting RC-IGBT device, comprising: a semiconductor substrate and an IGBT device body formed on the semiconductor substrate; the IGBT device body consists of an emitter, a gate, a collector and a field-limiting ring structure; the emitter region comprises a P+ type emitter region and an N type base region; the emitter region further comprises an N+ heavily doped region and an N- lightly doped region to form a composite buffer structure; the gate region comprises a gate oxide layer and a polysilicon filling layer; the collector region comprises an N+ doped region and a P+ buffer layer, the N+ doped region forms a PIN diode structure and is reversely connected in parallel with the IGBT device. Compared with the prior art, the invention reduces the voltage foldback phenomenon during forward conduction and improves the stability and reliability of the device by optimizing the thickness and doping concentration of the N+ doped region; adopts a trench gate structure to improve the withstand voltage and switching speed of the device and reduce the switching loss; by arranging the P+ buffer layer and the field-limiting ring structure, the thermal management performance and withstand voltage of the device are improved and the service life of the device is extended; a composite buffer structure is formed in the emitter region to reduce the conduction voltage drop and switching loss of the device.

[0071] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, not to limit them; although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be included in the scope of the claims and specification of the present invention. In particular, as long as there is no structural conflict, the various technical features mentioned in each embodiment can be combined in any way. The present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A reverse conducting RC-IGBT device, characterized in that: include: A semiconductor substrate and an IGBT device body formed on the semiconductor substrate; The IGBT device body is composed of an emitter, a gate, a collector and a field limiting ring structure; the emitter region includes a P+ type emitter region and an N type base region; the emitter region also includes an N+ heavily doped region and an N- lightly doped region to form a composite buffer structure; the gate region includes a gate oxide layer and a polysilicon filling layer; the collector region includes an N+ doped region and a P+ buffer layer, and the N+ doped region forms a PIN diode structure and is reversely connected in parallel with the IGBT device.

2. The reverse conducting RC-IGBT device according to claim 1, characterized in that: The IGBT device body also includes: a drift region; The drift region adopts a non-planar structure, and the non-planar structure has an arc-shaped transition area; the curvature radius of the non-planar structure is 50 microns-100 microns.

3. The reverse conducting RC-IGBT device according to claim 2, characterized in that: The drift region comprises: The thickness of the drift region is 40 microns to 120 microns; the doping concentration of the drift region is .

4. The reverse conducting RC-IGBT device according to claim 1, characterized in that: The composite buffer structure comprises: The thickness of the N+ heavily doped region in the composite buffer structure is 1 micron to 1.5 microns; the doping concentration of the N+ heavily doped region is The thickness of the N-lightly doped region in the composite buffer structure is 4 microns to 6 microns, and the doping concentration of the N-lightly doped region is .

5. The reverse conducting RC-IGBT device according to claim 1, characterized in that: The gate comprises: The length of the gate is 8 micrometers to 12 micrometers; the spacing between the gates is 4 micrometers to 6 micrometers.

6. The reverse conducting RC-IGBT device according to claim 1 or 5, characterized in that: The gate further comprises: The gate adopts a trench gate structure; the thickness of the gate oxide layer is 50 nanometers to 100 nanometers.

7. The reverse conducting RC-IGBT device according to claim 6, characterized in that: The trench gate structure comprises: The depth of the groove gate structure is 2 micrometers to 5 micrometers; the width of the groove gate structure is 0.5 micrometers to 2 micrometers.

8. The reverse conducting RC-IGBT device according to claim 1, characterized in that: The N+ doped region comprises: The doping concentration of the N+ doping region is ; The junction depth of the N+ doped region is 2 microns to 5 microns.

9. The reverse conducting RC-IGBT device according to claim 1, characterized in that: The P+ buffer layer comprises: The thickness of the P+ buffer layer is 1 micron to 5 microns; the doping concentration of the P+ buffer layer is .

10. The reverse conducting RC-IGBT device according to claim 1, characterized in that: The field limiting ring structure comprises: The width of the field limiting ring structure is 3 microns to 10 microns.

Images