IGBT structure and semiconductor device

Abstract

The application discloses an IGBT structure and a semiconductor device. The IGBT structure comprises a substrate, a drift region of a first conductive type, the drift region being arranged between a first main surface and a second main surface, a collector region of a second conductive type, the collector region being arranged on a side of the drift region facing the first main surface, a trench gate, the trench gate having at least two and being arranged at intervals, the trench gate extending from the second main surface to the drift region towards the first main surface, a floating region of the second conductive type, the floating region being arranged on a side of the drift region facing the second main surface and being located between the two trench gates, a body region of the second conductive type, the body region being arranged on a side of the drift region facing the second main surface, an emitter region of the first conductive type, the emitter region being arranged on a side of the body region facing the second main surface, and a doped region of the first conductive type, the doped region being arranged on both sides of the drift region between the two adjacent trench gates, and the doping concentration of the doped region being higher than that of the drift region. According to the IGBT structure and the semiconductor device, the control ability of the gate resistance on the opening di / dt can be effectively enhanced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of semiconductor technology, and in particular to an IGBT structure and a semiconductor device. BACKGROUND

[0002] Insulated Gate Bipolar Transistor (IGBT) is widely used in various power switching applications due to its excellent electrical characteristics and high tolerance to device destructive failure.

[0003] For IGBT structure with floating region, in the forward conduction state of IGBT structure, a large number of holes will accumulate in the P-type floating region and below it, resulting in injection enhancement and reducing the IGBT on-state voltage drop. However, when the IGBT structure is turned on, the hole accumulation in the floating region and the region below it charges the gate through the collector-gate capacitor, resulting in an increase in the gate voltage, and the turn-on current is not controlled by the gate resistance, and the turn-on di / dt controllability is poor.

[0004] Therefore, improvements are needed to at least partially solve the above problems. SUMMARY

[0005] The present application aims to at least partially solve the above problems. To this end, one object of the present application is to propose an IGBT structure with good turn-on di / dt controllability. Another object of the present application is to propose a semiconductor device with the IGBT structure.

[0006] The IGBT structure according to an embodiment of the present application comprises:

[0007] a substrate having a first main surface and a second main surface opposite to the first main surface, the first main surface and the second main surface being arranged vertically apart;

[0008] a drift region of a first conductivity type, the drift region being arranged between the first main surface and the second main surface;

[0009] a collector region of a second conductivity type, the collector region being arranged on a side of the drift region facing the first main surface, a side of the collector region away from the drift region constituting at least part of the first main surface;

[0010] trench gates, the trench gates being at least two and arranged apart, the trench gates extending from the second main surface to the drift region toward the first main surface;

[0011] a floating region of the second conductivity type, the floating region being disposed on a side of the drift region facing the second main surface and between two adjacent trench gates, a side of the floating region away from the drift region constituting part of the second main surface;

[0012] a body region of the second conductivity type, the body region being disposed on a side of the drift region facing the second main surface and on a side of the trench gate away from the floating region;

[0013] a emitter region of the first conductivity type, the emitter region being disposed on a side of the body region facing the second main surface, a side of the emitter region away from the body region constituting part of the second main surface;

[0014] a doped region of the first conductivity type, the doped region being disposed on both sides of the drift region between two adjacent trench gates and abutting the surface of the trench gate, the doped region having a doping concentration higher than that of the drift region.

[0015] In some examples of the present application, the doped region is in contact with the floating region, and the doped region extends along the surface of the trench gate from a side of the floating region facing the first main surface to a middle position of the bottom of the trench gate.

[0016] In some examples of the present application, the doped region abuts the surface of the trench gate extending from a side of the floating region facing the first main surface to the bottom of the trench gate.

[0017] In some examples of the present application, the width of the doped region is 0.2-0.4 μm.

[0018] In some examples of the present application, the doping concentration of the doped region is 1.5-2 times that of the drift region.

[0019] In some examples of the present application, the IGBT structure further comprises:

[0020] an insulating layer disposed on the second main surface and covering a side of the floating region away from the first main surface, a side of the trench gate away from the first main surface and part of the emitter region adjacent to the trench gate away from the first main surface;

[0021] an emitter metal covering the insulating layer and part of the second main surface, the emitter metal being in contact with the emitter region;

[0022] a collector metal disposed on the first main surface.

[0023] In some examples of the present application, the IGBT structure further comprises a contact region of the second conductivity type, which is arranged in parallel with the emitter region on a side of the body region facing the second main surface, and a side of the contact region away from the body region constitutes part of the second main surface, and the emitter metal contacts the contact region.

[0024] In some examples of the present application, the first conductivity type is N type.

[0025] The second conductivity type is P type.

[0026] In some examples of the present application, the trench gate comprises a gate trench extending from the second main surface to a drift region towards the first main surface, the gate dielectric layer on an inner surface of the gate trench, and a gate electrode on a side of the gate dielectric layer away from the inner surface of the gate trench.

[0027] The doped region is attached to a surface of the gate dielectric layer away from the gate electrode.

[0028] The semiconductor device according to an embodiment of the present application comprises the IGBT structure as described above.

[0029] The IGBT structure and the semiconductor device according to an embodiment of the present application can effectively improve the initial potential of the floating region at the moment when the IGBT structure is turned on, reduce the displacement current of the gate charging, enhance the control ability of the gate resistance on the turn-on di / dt, and improve the controllability of the turn-on di / dt, by arranging the doped region with a higher doping concentration than the drift region on both sides of the drift region between two trench gates. BRIEF DESCRIPTION OF DRAWINGS

[0030] The following drawings of the present application are hereby incorporated as part of the present application for the purpose of understanding the present application. The drawings of the embodiments of the present application and the description thereof are used to explain the devices and principles of the present application. In the drawings,

[0031] Figure 1 FIG. 1 is a schematic diagram of an IGBT structure in the related art;

[0032] Figure 2 FIG. 2 is a schematic diagram of an IGBT structure according to an embodiment of the present application;

[0033] Figure 3 FIG. 3 is a schematic diagram of the potential change of the floating region during the turn-on of the IGBT.

[0034] REFERENCE NUMERALS:

[0035] 100 - substrate, 101 - first major surface, 102 - second major surface, 110 - collector region, 120 - field stop region, 130 - drift region, 140 - trench gate, 141 - gate, 142 - gate dielectric layer, 150 - floating region, 160 - body region, 170 - emitter region, 180 - doped region;

[0036] 200 - insulating layer;

[0037] 300 - emitter metal;

[0038] 400 - collector metal. DETAILED DESCRIPTION

[0039] In the following description, numerous specific details are set forth to provide a more thorough understanding of the present application. However, it will be apparent to one of skill in the art that the present application can be practiced without one or more of these specific details. In other instances, well-known features have not been described in order to avoid obscuring the present application.

[0040] It should be understood that the present application can be carried out in various ways and that the application should not be interpreted as limited to the embodiments presented herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete and will fully convey the scope of the application to those skilled in the art. In the drawings, the sizes and relative sizes of layers and regions can be exaggerated for clarity. Like numbers refer to like elements throughout.

[0041] It should be understood that, although the terms first, second, third, etc. can be used herein to describe various elements, components, regions, layers and / or sections, these elements, components, regions, layers and / or sections should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or section from another element, component, region, layer or section. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the present application.

[0042] Spatially relative terms, such as "beneath", "below", "lower", "under", "above", "upper" and the like, can be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device described is turned over in use, a lower surface can be oriented upward and an upper surface can be oriented downward.

[0043] The purpose of the terms used herein is only to describe specific embodiments and is not intended to limit the present application. When used herein, the singular forms "a", "an", and "the" are intended to include the plural forms, unless the context clearly indicates otherwise. It should also be understood that the terms "comprising" and / or "including", when used in this specification, determine the presence of the features, integers, steps, operations, elements and / or parts, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, parts and / or groups. When used herein, the term "and / or" includes any and all combinations of the relevant listed items.

[0044] Embodiments of the invention are described herein with reference to cross-sectional views that are schematic diagrams of ideal embodiments (and intermediate structures) of the present application. Thus, variations in the shapes shown due to, for example, manufacturing techniques and / or tolerances can be expected. Therefore, the embodiments of the present application should not be limited to the specific shapes shown herein, but rather include shape deviations due to, for example, manufacturing. Therefore, what is shown in the figures is schematic in nature, and their shapes are not intended to show the actual shape of the device and are not intended to limit the scope of the present application.

[0045] First, refer to the attached Figure 1 The structure of an IGBT in the related art is exemplified. In the following description, N and P represent the conductivity type of the semiconductor. The following description assumes that the first conductivity type is N-type and the second conductivity type is P-type.

[0046] The IGBT structure according to the present invention mainly includes: a base 100, a drift region 130 of the first conductivity type, a collector region 110 of the second conductivity type, a trench gate 140, a floating region 150 of the second conductivity type, a body region 160 of the second conductivity type and an emitter region 170 of the first conductivity type.

[0047] The base 100 has a first main surface 101 and a second main surface 102 opposite to the first main surface 101 . The first main surface 101 and the second main surface 102 are spaced apart in the vertical direction.

[0048] The drift region 130 of the first conductivity type is provided between the first main surface 101 and the second main surface 102. The drift region 130 generally has a relatively low doping concentration, and therefore has a relatively high resistance and can withstand a relatively high voltage.

[0049] The collector region 110 of the second conductivity type is provided on a side of the drift region 130 facing the first main surface 101 , and a side of the collector region 110 away from the drift region 130 constitutes at least a portion of the first main surface 101 .

[0050] The trench gate 140 has at least two (two are shown in the figure) and is arranged at intervals, and the trench gate 140 extends from the second main surface 102 to the drift region 130 to the first main surface 101. The trench gate 140 includes a gate trench extending from the second main surface 102 to the first main surface 101 to the drift region 130, a gate dielectric layer 142 on the inner surface of the gate trench, and a gate electrode 141 on the side of the gate dielectric layer 142 away from the gate trench, and the gate electrode 141 is separated from the inner surface of the gate trench by the gate dielectric layer 142. Exemplarily, the gate dielectric layer 142 can be a silicon dioxide layer, and the gate electrode 141 can be polysilicon. The side of the trench gate 140 away from the first main surface 101 constitutes part of the second main surface 102. The arrangement of the trench gate 140 can form a more effective conduction channel, reduce the scattering and resistance of the carriers in the transmission process, and thus reduce the voltage drop in the on state. Lower on-state voltage drop means that the IGBT has lower power loss and higher efficiency under the same working current.

[0051] The floating region 150 of the second conductivity type (also referred to as the floating region) is arranged on the side of the drift region 130 facing the second main surface 102 and between the two trench gates 140, and the side of the floating region 150 away from the drift region 130 constitutes part of the second main surface 102. The floating region 150 is not directly connected to the external circuit and is in a "floating" state. The floating region 150 is mainly used to adjust the distribution of carriers in the drift region 130 in the on state.

[0052] The body region 160 of the second conductivity type (also referred to as the base region) is arranged on the side of the drift region 130 facing the second main surface 102 and on the side of the trench gate 140 away from the floating region 150, that is, in the horizontal direction of the trench gate 140, the body region 160 and the floating region 150 are arranged on the two sides of the trench gate 140, respectively. Figure 1

[0053] The emitter region 170 of the first conductivity type is arranged on the side of the body region 160 facing the second main surface 102, and the side of the emitter region 170 away from the body region 160 constitutes part of the second main surface 102. The doping concentration of the emitter region of the first conductivity type is higher than the doping concentration of the drift region 130.

[0054] In the on state of the IGBT structure, holes are injected from the collector region 110 to the drift region 130, and reach the emitter region through the body region 160. Since the floating region 150 is not electrically connected to the emitter region and other external circuits, a large number of holes will accumulate in the floating region 150 and below, resulting in injection enhancement and reducing the on-state voltage drop of the IGBT. However, when the IGBT structure is turned on, the accumulation of holes in the floating region 150 and the area below will charge the gate electrode through the collector-gate capacitor, resulting in an increase in the gate voltage, and the turn-on current is not controlled by the gate resistance, and the controllability of the di / dt (current change rate) of the turn-on is poor.​

[0055] Further, referring to the attached drawings, Figure 1 The IGBT structure further comprises a field stop region 120 of the first conductivity type, which is disposed between the collector region 110 and the drift region 130, and the doping concentration of the field stop region 120 is higher than that of the drift region 130. The main function of the field stop region 120 is to terminate the electric field in the off state of the IGBT, preventing the electric field from penetrating into the collector region 110, thereby improving the withstand voltage capability of the device. When a high voltage is applied, the field stop region 120 can bear a part of the electric field, so that the electric field gradually weakens before reaching the collector region 110, avoiding the breakdown of the collector region 110. The field stop region 120 can also reduce the duration and amplitude of the tail current by adjusting the carrier distribution and extraction speed. The reduction of the tail current helps to reduce the off-state loss.

[0056] The IGBT structure can achieve significant improvement in the trade-off relationship between the on-state voltage drop (Von) and the off-state loss (Eoff) by setting the trench gate 140 and the field stop region 120.

[0057] In some embodiments, the field stop region 120 can not be provided in the IGBT structure, and the side of the drift region 130 facing the first main surface 101 directly contacts the collector region 110.

[0058] Further, referring to the attached drawings, Figure 1 The IGBT structure further comprises an insulating layer 200, an emitter metal 300 and a collector metal 400.

[0059] The insulating layer 200 is disposed on the second main surface 102, and covers the side of the floating region 150 away from the first main surface 101, the side of the trench gate 140 away from the first main surface 101, and the side of the partial emitter region 170 adjacent to the trench gate 140 away from the first main surface 101. Exemplarily, the insulating layer 200 can be a silicon dioxide layer. The emitter metal 300 covers part of the second main surface 102 and the insulating layer 200, and the emitter metal 300 contacts the emitter region 170 to form an electrically conductive connection. The insulating layer 200 is used to insulate between the emitter metal 300 and the gate 141 and the floating region 150. The collector metal 400 is disposed on the first main surface 101 and contacts the collector layer. The emitter metal 300 and the collector metal 400 are respectively used to realize the electrical lead-out of the emitter region and the collector region 110.

[0060] Referring to the attached drawings, Figure 2 An IGBT structure according to an embodiment of the present application is exemplarily described. In the following description, N and P represent the conductivity type of the semiconductor. In the following, the first conductivity type is set as N type, and the second conductivity type is set as P type.

[0061] The IGBT structure mainly comprises a substrate 100, a drift region 130 of a first conductivity type, a collector region 110 of a second conductivity type, a trench gate 140, a floating region 150 of the second conductivity type, a body region 160 of the second conductivity type, an emitter region 170 of the first conductivity type, and a doped region 180 of the first conductivity type.

[0062] The substrate 100 has a first main surface 101 and a second main surface 102 opposite to the first main surface 101, and the first main surface 101 and the second main surface 102 are arranged in a vertical direction.

[0063] The drift region 130 of the first conductivity type is arranged between the first main surface 101 and the second main surface 102. The drift region 130 generally has a lower doping concentration, and thus has a higher resistance and can withstand a higher voltage.

[0064] The collector region 110 of the second conductivity type is arranged on a side of the drift region 130 facing the first main surface 101, and a side of the collector region 110 away from the drift region 130 constitutes at least part of the first main surface 101.

[0065] The trench gate 140 has at least two (two are shown in the figure) and is arranged in a spaced manner, and the trench gate 140 extends from the second main surface 102 to the drift region 130 of the first main surface 101. The trench gate 140 comprises a gate trench extending from the second main surface 102 to the drift region 130 of the first main surface 101, a gate dielectric layer 142 on the inner surface of the gate trench, and a gate electrode 141 on a side of the gate dielectric layer 142 away from the inner surface of the gate trench, and the gate electrode 141 is isolated from the inner surface of the gate trench by the gate dielectric layer 142. Exemplarily, the gate dielectric layer 142 can be a silicon dioxide layer, and the gate electrode 141 can be polysilicon. A side of the trench gate 140 away from the first main surface 101 constitutes part of the second main surface 102. The arrangement of the trench gate 140 can form a more effective conduction channel, reduce the scattering and resistance of the carriers in the transmission process, and thus reduce the voltage drop in the on-state. A lower on-state voltage drop means that the IGBT has a smaller power loss and is more efficient under the same working current.

[0066] The floating region 150 of the second conductivity type (also referred to as the floating region) is arranged on a side of the drift region 130 facing the second main surface 102 and located between the adjacent two trench gates 140, and a side of the floating region 150 away from the drift region 130 constitutes part of the second main surface 102. The floating region 150 is not directly connected to the external circuit and is in a "floating" state. The floating region 150 is mainly used to adjust the distribution of the carriers in the drift region 130 in the on-state.

[0067] The body region 160 of the second conductivity type (also referred to as the base region) is arranged on a side of the drift region 130 facing the second main surface 102 and located on a side of the trench gate 140 away from the floating region 150, that is, on a side of the trench gate 140 away from the floating region 150.Figure 1 In the horizontal direction, the body region 160 and the floating region 150 are respectively arranged on both sides of the trench gate 140.

[0068] The emitter region 170 of the first conductivity type is provided on the side of the body region 160 facing the second main surface 102 , and the side of the emitter region 170 away from the body region 160 constitutes part of the second main surface 102 . The doping concentration of the emitter region of the first conductivity type is higher than that of the drift region 130 .

[0069] The first conductive type doping region 180 is disposed on both sides of the drift region 130 between two adjacent trench gates 140 (i.e. Figure 2 The doping region 180 is bonded to the surface of the trench gate 140 on the left and right sides of the drift region 130 between the two trench gates 140, that is, on both sides of the drift region 130 below the floating region 150 (in the direction of the floating region 150 toward the first main surface 101). Specifically, the doping region 180 is bonded to the surface of the gate dielectric layer 142 on the side away from the gate electrode 141. It should be noted that the bonding described in this application means that the two form direct contact. The doping concentration of the doping region 180 is higher than the doping concentration of the drift region 130, that is, the doping region 180 has a higher concentration of electrons than the drift region 130.

[0070] When the IGBT structure is in the forward conduction state, holes are injected from the collector region 110 into the drift region 130 and reach the emitter region through the body region 160. Since the floating region 150 is not electrically connected to the emitter region and other external circuits, a large number of holes will accumulate in the floating region 150 and below, resulting in injection enhancement, which reduces the IGBT conduction voltage drop.

[0071] During the IGBT turn-on process, the holes accumulated in the floating region 150 and the area below it form a displacement current through the collector-gate capacitance to charge the gate 141. The magnitude of the displacement current charging the gate 141 is positively correlated with the difference between the initial potential and the peak potential of the floating region 150 (the greater the difference between the initial potential and the peak potential, the greater the displacement current). In this embodiment, by adding doped regions 180 on both sides of the drift region 130 below the floating region 150, which are in contact with the surface of the trench gate 140 and have a higher doping concentration than that of the drift region, the initial potential of the floating region 150 can be increased, and the difference between the initial potential and the peak potential of the floating region 150 during the turn-on process can be reduced. Therefore, the displacement current charging the gate 141 can be reduced, and the gate resistance's control over the turn-on di / dt can be enhanced.

[0072] Further, see Appendix Figure 2In the embodiment, the doped region contacts the floating region, the doped region 180 extends along the surface of the trench gate 140 (i.e. the surface of the gate dielectric layer 142) from the floating region 150 to the bottom of the trench gate 140 on the side of the trench gate 140 facing the first main surface 101, in particular, the top side of the doped region 180 (i.e. the side of the doped region 180 facing the second main surface 102) contacts the bottom side of the floating region 150 (i.e. the side of the floating region 150 facing the first main surface 101), and the lower part of the doped region 180 can extend to the center of the bottom of the trench gate 140. That is, in the embodiment, the doped region 180 extends to the surface of the trench gate 140 at the position where the trench gate 140 contacts the bottom side of the floating region 150 (i.e. the position of the trench gate 140 facing the first main surface 101) to the center of the bottom of the trench gate 140. By arranging the doped region 180 at the above position, the accumulation of holes in the region below the floating region 150 during the turn-on of the IGBT can be effectively reduced, and the displacement current formed by the collector-gate capacitance can be effectively charged to the gate 141, thereby enhancing the control ability of the gate resistance on the di / dt during the turn-on. Figure 2 In the embodiment, the doped region contacts the floating region, the doped region 180 extends along the surface of the trench gate 140 (i.e. the surface of the gate dielectric layer 142) from the floating region 150 to the bottom of the trench gate 140 on the side of the trench gate 140 facing the first main surface 101, in particular, the top side of the doped region 180 (i.e. the side of the doped region 180 facing the second main surface 102) contacts the bottom side of the floating region 150 (i.e. the side of the floating region 150 facing the first main surface 101), and the lower part of the doped region 180 can extend to the center of the bottom of the trench gate 140. That is, in the embodiment, the doped region 180 extends to the surface of the trench gate 140 at the position where the trench gate 140 contacts the bottom side of the floating region 150 (i.e. the position of the trench gate 140 facing the first main surface 101) to the center of the bottom of the trench gate 140. By arranging the doped region 180 at the above position, the accumulation of holes in the region below the floating region 150 during the turn-on of the IGBT can be effectively reduced, and the displacement current formed by the collector-gate capacitance can be effectively charged to the gate 141, thereby enhancing the control ability of the gate resistance on the di / dt during the turn-on.

[0073] In some other embodiments, the doped region 180 can extend to the surface of the trench gate 140 at the position where the trench gate 140 contacts the bottom side of the floating region 150 (i.e. the position of the trench gate 140 facing the first main surface 101) to the bottom of the trench gate 140 (e.g. the center of the bottom of the trench gate 140). For example, the upper part of the doped region 180 can contact the floating region 150, and the lower part of the doped region 180 can extend to the center of the bottom of the trench gate 140. Figure 2

[0074] Further, referring to FIG. 2, the width of the doped region 180 is 0.2 μm-0.4 μm. It should be noted that the width herein refers to the thickness in the direction perpendicular to the surface of the trench gate 140. By arranging the width of the doped region 180 in the above range, the formation of the hole blocking path and the carrier storage layer can be effectively avoided, and the injection enhancement effect can be reduced. Figure 2

[0075] ​​Furthermore, in this embodiment, the doping concentration of the doping region 180 is 1.5-2 times the doping concentration of the drift region 130. If the doping concentration of the doping region 180 is too low (e.g., less than 1.5 times the doping concentration of the drift region 130), it will not help raise the initial potential of the floating region 150. If the doping concentration of the doping region 180 is too high (e.g., more than 2 times the doping concentration of the drift region 130), it will cause voltage withstand issues. By setting the doping concentration of the doping region 180 within the above range, the initial potential of the floating region 150 can be effectively raised while avoiding voltage withstand issues.

[0076] See attached Figure 3 , attached Figure 3 Schematic diagram of the potential change of the floating region 150 during the IGBT turn-on process. The red line in the figure represents the IGBT structure of this embodiment (i.e. Figure 2 The P-type floating region 150 potential in the IGBT structure shown in FIG. 1 is a potential of the P-type floating region 150 in the IGBT structure shown in FIG. 1 , and the black line represents the IGBT structure in the related art (ie Figure 1 The potential of the P-type floating region 150 in the IGBT structure shown in FIG. Figure 3 It can be seen that compared with the IGBT structure in the related art, the difference between the peak potential and the initial potential of the P-type floating region 150 of the IGBT structure of this embodiment is significantly reduced, thereby effectively reducing the displacement current charging the gate 141, reducing its impact on the IGBT turn-on current, and enhancing the gate resistance's control ability over the turn-on di / dt.

[0077] Further, see Appendix Figure 2 In this embodiment, the IGBT structure further includes a field stop region 120 of the first conductivity type. The field stop region 120 is provided between the collector region 110 and the drift region 130. The doping concentration of the field stop region 120 is higher than the doping concentration of the drift region 130. The main function of the field stop region 120 is to terminate the electric field when the IGBT is in the off state, preventing the electric field from penetrating into the collector region 110, thereby improving the voltage withstand capability of the device. When a high voltage is applied, the field stop region 120 can withstand a portion of the electric field, so that the electric field gradually weakens before reaching the collector region 110, thereby avoiding breakdown of the collector region 110. The field stop region 120 can also reduce the duration and amplitude of the tail current by adjusting the carrier distribution and extraction speed. The reduction of the tail current helps to reduce the turn-off loss.

[0078] The IGBT structure can achieve significant improvement in the trade-off between the on-state voltage drop (Von) and the off-state loss (Eoff) by providing the trench gate 140 and the field stop region 120 .

[0079] In some embodiments, the field stop region 120 may not be provided in the IGBT structure, and the side of the drift region 130 facing the first main surface 101 is directly in contact with the collector region 110 .

[0080] Further, see Appendix Figure 2 In this embodiment, the IGBT structure further includes an insulating layer 200 , an emitter metal 300 and a collector metal 400 .

[0081] The insulating layer 200 is provided on the second main surface 102 and covers the side of the floating region 150 away from the first main surface 101, the side of the trench gate 140 away from the first main surface 101, and the side of the portion of the emitter region 170 adjacent to the trench gate 140 away from the first main surface 101. For example, the insulating layer 200 can be a silicon dioxide layer. The emitter metal 300 covers the insulating layer 200 and a portion of the second main surface 102. The emitter metal 300 contacts the emitter region 170 to form a conductive connection. The insulating layer 200 is used to insulate the emitter metal 300 from the gate 141 and the floating region 150. The collector metal 400 is provided on the first main surface 101 and contacts the collector region 110. The emitter metal 300 and the collector metal 400 are used to electrically connect the emitter region 170 and the collector region 110, respectively.

[0082] In some embodiments, the IGBT structure further includes a contact region of the second conductivity type, and the contact region and the emitter region 170 are arranged in parallel on the side of the body region 160 facing the second main surface 102, that is, the contact region and the emitter region 170 can be arranged on the side of the body region 160 facing the second main surface 102. Figure 2 The emitter region 170 and the contact region 300 are arranged in parallel in the horizontal direction of the body region 160. The side of the contact region away from the body region 160 constitutes part of the second main surface 102, and the emitter metal 300 contacts the contact region. The doping concentration of the contact region is higher than that of the body region 160. By simultaneously providing the emitter region 170 of the first conductivity type and the contact region of the second conductivity type, the current output capability of the IGBT device is effectively improved.

[0083] The present application also provides a semiconductor device, which includes the above-mentioned IGBT structure. The semiconductor device may be a power semiconductor device.

[0084] Although example embodiments have been described herein with reference to the accompanying drawings, it should be understood that the above example embodiments are merely illustrative and are not intended to limit the scope of the present application. Various changes and modifications may be made therein by those skilled in the art without departing from the scope and spirit of the present application. All such changes and modifications are intended to be included within the scope of the present application as required by the appended claims.

[0085] In the description provided herein, a large number of specific details are described. However, it is understood that the embodiments of the present application can be practiced without these specific details. In some instances, well-known methods, structures, and techniques are not shown in detail so as not to obscure the understanding of this description.

[0086] Similarly, it is to be understood that the embodiments of the present application can be used in any combination, whether such combinations are specifically noted herein or not. For example, the methods of the present application can be used in combination with any of the apparatuses of the present application, and vice versa. Furthermore, the methods of the present application can be used in combination with other methods of the present application, and the apparatuses of the present application can be used in combination with other apparatuses of the present application. Descriptions of a single embodiment or a single variation intended to cover all embodiments whether or not additional modifications are noted in connection with other embodiments. Thus, the claims following the detailed description are hereby expressly incorporated into this detailed description. Claims, describing at least the preferred combinations of constituent elements that cooperate to attain the claimed and desired results, operate for their intended purposes, and realize the objects to be achieved.

[0087] Those skilled in the art will appreciate that all features described herein (including all accompanying claims, abstract and drawings), and steps of any method or processes disclosed herein can be combined in any combination, except where features are mutually exclusive (to the extent such exceptions have been

[0088] Furthermore, those skilled in the art will recognize that references to conventional methodology are incorporated by reference in a manner consistent with the present application. Although specific embodiments of the application have been described herein, the scope of the application should not be limited to particular embodiments, but should instead cover each and every novel method and device particularly pointed out and set forth in part removed from the context, or otherwise described prior to the application hereof.

[0089] It is to be understood that the above description is intended to be illustrative, and not restrictive. Many other embodiments will be apparent to those of skill in the art upon reviewing the above description. The scope of the application should, therefore, be determined not with reference to the above description, but instead should be determined with reference to the appended claims, along with their full scope of equivalents.

Claims

1. An IGBT structure, characterized in that: include: a substrate having a first main surface and a second main surface opposite to the first main surface, wherein the first main surface and the second main surface are spaced apart in a vertical direction; a drift region of a first conductivity type, the drift region being provided between the first main surface and the second main surface; a collector region of a second conductivity type, the collector region being provided on a side of the drift region facing the first main surface, and a side of the collector region away from the drift region constituting at least a portion of the first main surface; Trench gates, at least two of which are spaced apart from each other, extending from the second main surface to the first main surface into the drift region; a floating region of the second conductivity type, the floating region being disposed on a side of the drift region facing the second main surface and between two adjacent trench gates, and a side of the floating region away from the drift region constituting a portion of the second main surface; a body region of a second conductivity type, the body region being disposed on a side of the drift region facing the second main surface and on a side of the trench gate away from the floating region; an emitter region of a first conductivity type, the emitter region being provided on a side of the body region facing the second main surface, and a side of the emitter region away from the body region constituting a portion of the second main surface; a doping region of a first conductivity type, wherein the doping region is disposed on both sides of the drift region between two adjacent trench gates and is in contact with the surface of the trench gate, the doping region is located on a side of the floating region facing the first main surface, and the doping concentration of the doping region is higher than the doping concentration of the drift region.

2. The IGBT structure according to claim 1, characterized in that: The doped region contacts the floating region, and the doped region extends from the floating region toward the first main surface along the surface of the trench gate to the bottom of the trench gate.

3. The IGBT structure according to claim 1, characterized in that: The doped region is in contact with a portion of the surface of the trench gate extending from the floating region toward the first main surface to the bottom of the trench gate.

4. The IGBT structure according to claim 1, wherein: The width of the doping region is 0.2 μm-0.4 μm.

5. The IGBT structure according to claim 1, wherein: The doping concentration of the doping region is 1.5-2 times the doping concentration of the drift region.

6. The IGBT structure according to claim 1, characterized in that: The IGBT structure further includes: an insulating layer, provided on the second main surface, and covering a side of the floating region away from the first main surface, a side of the trench gate away from the first main surface, and a side of a portion of the emitter region adjacent to the trench gate away from the first main surface; an emitter metal covering the insulating layer and a portion of the second main surface, the emitter metal being in contact with the emitter region; The collector metal is provided on the first main surface.

7. The IGBT structure according to claim 6, characterized in that: The IGBT structure also includes a contact region of a second conductivity type, which is arranged in parallel with the emitter region on the side of the body region facing the second main surface. The side of the contact region away from the body region constitutes part of the second main surface, and the emitter metal is in contact with the contact region.

8. The IGBT structure according to claim 1, characterized in that: The first conductivity type is N type; The second conductivity type is P type.

9. The IGBT structure according to claim 1, wherein: The trench gate comprises a gate trench extending from the second main surface to the first main surface to the drift region, a gate dielectric layer located on an inner surface of the gate trench, and a gate located on a side of the gate dielectric layer away from the inner surface of the gate trench; The doped region is in contact with a surface of the gate dielectric layer away from the gate.

10. A semiconductor device, characterized in that: The invention comprises the IGBT structure according to any one of claims 1 to 9.

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