IGBT structure and semiconductor device

Abstract

The invention discloses an IGBT (Insulated Gate Bipolar Translator) structure and a semiconductor device. The IGBT structure comprises a substrate and a drift region of a first conduction type, wherein the drift region is arranged between a first main surface and a second main surface; the collector region is arranged on one side, facing the first main surface, of the drift region; the number of the trench gates is at least two, the trench gates are arranged at intervals, and the trench gates extend into the drift region from the second main surface to the first main surface; the floating region of the second conduction type is arranged on one side, facing the second main surface, of the drift region and is positioned between the two trench gates; the body region of the second conduction type is arranged on one side, facing the second main surface, of the drift region; the emitter region of the first conductive type is arranged on one side, facing the second main surface, of the body region; and the doped regions of the first conduction type are arranged on the two sides of the drift region between the two adjacent trench gates, and the doping concentration of the doped regions is higher than that of the drift region. According to the IGBT structure and the semiconductor device provided by the invention, the control capability of the gate resistor to turn on di / dt can be effectively enhanced.

Description

Technical Field

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

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

[0003] For an IGBT structure with a floating region, when the IGBT structure is in the forward conduction state, a large number of holes will accumulate in the P-type floating region and below it, resulting in injection enhancement, which reduces the IGBT conduction voltage drop. However, when the IGBT structure is turned on, the accumulated holes in the floating region and the area below it charge the gate through the collector-gate capacitance, resulting in an increase in the gate voltage. The turn-on current is not controlled by the gate resistance, and the turn-on di / dt (current change rate) is poorly controllable.

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

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

[0006] The IGBT structure according to an embodiment of the present invention includes:

[0007] A substrate, the 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 spaced apart in a vertical direction;

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

[0009] A collector region of a second conductivity type, the collector region being disposed 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;

[0010] A trench gate, wherein there are at least two trench gates arranged at intervals, and the trench gates extend from the second main surface to the first main surface into the drift region;

[0011] A floating region of the second conductivity type, the floating region is arranged 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 constitutes a 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] An emitter region of a first conductivity type, the emitter region being disposed 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;

[0014] A doping region of a first conductivity type is disposed on both sides of the drift region between the two trench gates and is in contact with the surface of the trench gates. The doping concentration of the doping region is higher than the doping concentration of the drift region.

[0015] In some examples of the present invention, 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 a middle position of the bottom of the trench gate.

[0016] In some examples of the present invention, the doped region is aligned 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.

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

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

[0019] In some examples of the present invention, the IGBT structure further includes:

[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 a side of a portion of the emitter region adjacent to the trench gate away from the first main surface;

[0021] 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;

[0022] The collector metal is provided on the first main surface.

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

[0024] In some examples of the present invention, the first conductivity type is N type;

[0025] The second conductivity type is P type.

[0026] In some examples of the present invention, the trench gate includes a gate trench extending from the second main surface to the first main surface to the drift region, the gate dielectric layer located on the 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;

[0027] The doped region is in contact with a surface of the gate dielectric layer at a side away from the gate.

[0028] The semiconductor device according to the embodiment of the present invention includes the IGBT structure as described above.

[0029] According to the IGBT structure and semiconductor device of the embodiment of the present invention, by arranging doping regions with a doping concentration higher than the doping concentration of the drift region on both sides of the drift region between the two trench gates, the initial potential of the floating region immediately before the IGBT structure is turned on can be effectively improved, the displacement current of the gate charging is reduced, the controllability of the gate resistance on the turn-on di / dt is enhanced, and the controllability of the turn-on di / dt is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The following drawings of the present application are hereby used as part of the present application for understanding the present application. The drawings show the embodiments of the present application and their descriptions, and are used to explain the device and principle of the present application. In the drawings,

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

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

[0033] Figure 3 Schematic diagram of the potential change in the floating area during the IGBT turn-on process.

[0034] Description of reference numerals:

[0035] 100 - substrate, 101 - first main surface, 102 - second main 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 - doping region;

[0036] 200-insulation layer;

[0037] 300-emitter metal;

[0038] 400 - Collector Metal. DETAILED DESCRIPTION

[0039] In the following description, a large number of specific details are provided to provide a more thorough understanding of the present application. However, it is apparent to those skilled in the art that the present application can be implemented without one or more of these details. In other examples, in order to avoid confusion with the present application, some technical features well known in the art are not described.

[0040] It should be understood that the present application can be implemented in different forms and should not be construed as being limited to the embodiments presented herein. On the contrary, providing these embodiments will make the disclosure thorough and complete and fully convey the scope of the present application to those skilled in the art. In the accompanying drawings, the sizes and relative sizes of layers and regions may be exaggerated for clarity. The same reference numerals throughout represent the same elements.

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

[0042] Spatially relative terms such as "under", "beneath", "below", "under", "above", "above", etc., may be used herein for convenience of description to describe the relationship of one element or feature to other elements or features shown in the figures. It should be understood that the spatially relative terms are intended to encompass different orientations of the device in use and operation in addition to the orientation shown in the figures.

[0043] The purpose of the terms used herein is only to describe specific embodiments and is not intended to be limiting of the present application. When used herein, the singular forms "one", "an" and "said / the" are also intended to include plural forms, unless the context clearly indicates otherwise. It should also be understood that the terms "consisting of" and / or "comprising", 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 as 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, embodiments of the present application should not be limited to the specific shapes shown herein, but 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 display 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 An IGBT structure in the related art is described by way of example. In the following description, N and P represent the conductivity type of a semiconductor. In the following description, the first conductivity type is set to be N type and the second conductivity type is set to be P type.

[0046] The IGBT structure according to the present invention mainly includes: 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 a second conductivity type, a body region 160 of a second conductivity type and an emitter region 170 of a first conductivity type.

[0047] The base body 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 disposed between the first main surface 101 and the second main surface 102. The drift region 130 generally has a lower doping concentration, so it has a higher resistance and can withstand a higher voltage.

[0049] The collector region 110 of the second conductivity type is disposed 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] There are at least two (two shown in the figure) trench gates 140 and they are arranged at intervals. The trench gates 140 extend from the second main surface 102 to the first main surface 101 to the drift region 130. 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 located on the inner surface of the gate trench, and a gate 141 located on the side of the gate dielectric layer 142 away from the gate trench. The gate 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 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 conductive channel, reduce the scattering and resistance of carriers during transmission, and thus reduce the voltage drop in the on state. Lower on-state voltage drop means that at the same operating current, the IGBT has less power loss and higher efficiency.

[0051] The second conductive type floating region 150 (also called 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. 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 second conductive type body region 160 (also referred to as the base region) is disposed 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. Figure 1 In the horizontal direction, the body region 160 and the floating region 150 are respectively disposed on both sides of the trench gate 140 .

[0053] The emitter region 170 of the first conductivity type is disposed 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 forward conduction state of the IGBT structure, 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. However, when the IGBT structure is turned on, the holes accumulated in the floating region 150 and the area below it charge the gate through the collector-gate capacitance, 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 (current change rate) controllability is poor.

[0055] Further, see Appendix Figure 1 The IGBT structure also includes a field stop region 120 of the first conductivity type, which is arranged between the collector region 110 and the drift region 130, and 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 turned off, to prevent 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 withstand 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 turn-off 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 providing the trench gate 140 and the field stop region 120 .

[0057] 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 .

[0058] Further, see Appendix Figure 1 The IGBT structure further includes an insulating layer 200 , an emitter metal 300 and a collector metal 400 .

[0059] The insulating layer 200 is arranged on the second main surface 102, and covers the side of the floating area 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 part of the emitter area 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 area 170 to form a conductive connection. The insulating layer 200 is used to insulate between the emitter metal 300 and the gate 141 and the floating area 150. The collector metal 400 is arranged on the first main surface 101 and contacts the collector layer. The emitter metal 300 and the collector metal 400 are used to realize the electrical extraction of the emitter area and the collector area 110, respectively.

[0060] See attached Figure 2 The structure of an IGBT according to an embodiment of the present invention is described as an example. In the following description, N and P represent the conductivity type of the semiconductor. In the following description, the first conductivity type is set as N type and the second conductivity type is set as P type.

[0061] The IGBT structure mainly includes: 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 a second conductivity type, a body region 160 of a second conductivity type, an emitter region 170 of a first conductivity type, and a doped region 180 of a first conductivity type.

[0062] The base body 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.

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

[0064] The collector region 110 of the second conductivity type is disposed 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 .

[0065] There are at least two (two shown in the figure) trench gates 140 and they are arranged at intervals. The trench gates 140 extend from the second main surface 102 to the first main surface 101 to the drift region 130. 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 located on the inner surface of the gate trench, and a gate 141 located on the side of the gate dielectric layer 142 away from the inner surface of the gate trench, and the gate 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 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 conductive channel, reduce the scattering and resistance of carriers during transmission, and thus reduce the voltage drop in the on state. Lower on-state voltage drop means that at the same operating current, the IGBT has less power loss and higher efficiency.

[0066] The second conductive type floating region 150 (also called floating region) is arranged on the side of the drift region 130 facing the second main surface 102 and between two adjacent trench gates 140. 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.

[0067] The second conductive type body region 160 (also referred to as the base region) is disposed 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. Figure 1 In the horizontal direction, the body region 160 and the floating region 150 are respectively disposed on both sides of the trench gate 140 .

[0068] The emitter region 170 of the first conductivity type is disposed 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 .

[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 away from the gate 141. It should be noted that the bonding described in the present 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 via 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, thereby reducing the on-state voltage drop of the IGBT.

[0071] During the IGBT turn-on process, 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, and the magnitude of the displacement current for 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 doping 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 for charging the gate 141 can be reduced, and the control capability of the gate resistor over the turn-on di / dt is enhanced.

[0072] Further, see Appendix Figure 2In this embodiment, the doping region is in contact with the floating region, and the doping region 180 extends from the side of the floating region 150 toward the first main surface 101 along the surface of the trench gate 140 (that is, the surface of the gate dielectric layer 142) to the bottom of the trench gate 140. Specifically, the top side of the doping region 180 (the side of the doping region 180 toward the second main surface 102) is in contact with the bottom side of the floating region 150 (the side of the floating region 150 toward the first main surface 101), and the lower part of the doping region 180 can extend to the center of the bottom of the trench gate 140. That is, in this embodiment, the doping region 180 and the side of the trench gate 140 from the floating region 150 toward the first main surface 101 (that is, Figure 2 The doping region 180 is arranged at the above position, so that the accumulation of holes in the area below the floating region 150 when the IGBT is turned on can be effectively reduced, and the gate 141 can be charged by the collector-gate capacitance to form a displacement current, thereby enhancing the control ability of the gate resistance to the turn-on di / dt. It should be noted that the bottom of the doping region 180 does not exceed the center of the bottom of the trench gate 140, and the doping region 180 does not extend to the part of the drift region 130 located on the side of the trench gate 140 facing the body region 160.

[0073] In some other embodiments, the doped region 180 may be adjacent to the side of the trench gate 140 that faces the first main surface 101 from the floating region 150 (ie, Figure 2 The doped region 180 may extend from the position where the middle trench gate 140 contacts the lower surface of the floating region 150 to the portion of the surface at the bottom of the trench gate 140 (e.g., the center of the bottom of the trench gate 140). Exemplarily, the upper portion of the doped region 180 may contact the non-floating region 150, but be separated by a short distance. Exemplarily, the doped region 180 may not extend along the surface of the trench gate 140 to the center of the bottom of the trench gate 140, that is, the doped region 180 may not be attached to the surface of the portion of the trench gate 140 near the center of the bottom of the trench gate 140.

[0074] Further, see Appendix Figure 2 In this embodiment, the width of the doping region 180 is 0.2 μm-0.4 μm. It should be noted that the width here refers to the thickness in the direction perpendicular to the surface of the trench gate 140. By setting the width of the doping region 180 within the above range, it is possible to effectively avoid the formation of a blocking hole path, generate a carrier storage layer, and aggravate the injection enhancement effect.

[0075] Further, in the present 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., lower than 1.5 times the doping concentration of the drift region 130), it will not play a role in raising the initial potential of the floating region 150, and if the doping concentration of the doping region 180 is too high (e.g., higher than 2 times the doping concentration of the drift region 130), it will cause a withstand voltage problem. 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 and the withstand voltage problem can be avoided.

[0076] See attached Figure 3 , attached Figure 3 FIG. 1 is a 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 in 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 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, and the field stop region 120 is arranged between the collector region 110 and the drift region 130, and 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 turned off, to prevent 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 withstand a part of the electric field, so that the electric field gradually weakens before reaching the collector region 110, thereby 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 turn-off loss.

[0078] 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 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 part of the 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 the insulating layer 200 and part of the second main surface 102, and the emitter metal 300 contacts the emitter region 170 to form a 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 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 realize the electrical extraction of 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 a 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 second conductive type. Figure 2 The contact region 170 and the contact region 300 are arranged in parallel in the horizontal direction of the body region 160, and 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 capacity of the IGBT device is effectively improved.

[0083] The present application also provides a semiconductor device, which includes the IGBT structure described above. 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 exemplary and are not intended to limit the scope of the present application to this. Those of ordinary skill in the art may make various changes and modifications therein without departing from the scope and spirit of the present application. All these 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 should be understood that in order to streamline the present application and help understand one or more of the various inventive aspects, in the description of the exemplary embodiments of the present application, the various features of the present application are sometimes grouped together into a single embodiment, figure, or description thereof. However, the method of the present application should not be interpreted as reflecting the following intention: the claimed application requires more features than the features clearly stated in each claim. More specifically, as reflected in the corresponding claims, the inventive point is that the corresponding technical problem can be solved with features less than all the features of a single disclosed embodiment. Therefore, the claims following the specific embodiment are hereby explicitly incorporated into the specific embodiment, wherein each claim itself serves as a separate embodiment of the present application.

[0087] It will be understood by those skilled in the art that, except for mutually exclusive features, all features disclosed in this specification (including the accompanying claims, abstracts and drawings) and all processes or units of any method or device disclosed in this specification may be combined in any combination. Unless otherwise expressly stated, each feature disclosed in this specification (including the accompanying claims, abstracts and drawings) may be replaced by an alternative feature that provides the same, equivalent or similar purpose.

[0088] In addition, those skilled in the art will appreciate that, although some embodiments described herein include certain features included in other embodiments but not other features, the combination of features of different embodiments is meant to be within the scope of the present application and form different embodiments. For example, in the claims, any one of the claimed embodiments can be used in any combination.

[0089] It should be noted that the above-mentioned embodiments illustrate rather than limit the invention and that those skilled in the art will be able to design alternative embodiments without departing from the scope of the appended claims.

Claims

1. An IGBT structure, characterized in that: include: A substrate, the 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 spaced apart in a vertical direction; a drift region of a first conductivity type, the drift region being disposed between the first main surface and the second main surface; A collector region of a second conductivity type, the collector region being disposed 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; A trench gate, wherein there are at least two trench gates arranged at intervals, and the trench gates extend 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 is arranged 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 constitutes a part of the second main surface; 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; An emitter region of a first conductivity type, the emitter region being disposed 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 is disposed on both sides of the drift region between two adjacent trench gates and is in contact with surfaces of the trench gates. 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 is in contact with 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, characterized in that: The width of the doping region is 0.2 μm-0.4 μm.

5. The IGBT structure according to claim 1, characterized in that: 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, 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 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 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 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, characterized in that: 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 the 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 at a side 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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