RC-igbt with igbt section and diode section

Abstract

An RC IGBT having an IGBT section and a diode section is disclosed. An RC IGBT (1) is provided having an n-barrier region (107) in a transition section (1-23) between a diode section (1-22) and an IGBT section (1-21).

Description

Technical Field

[0001] This specification relates to embodiments of RC IGBTs and embodiments of methods for forming RC IGBTs. In particular, this specification relates to embodiments of RC IGBTs and embodiments of methods for forming RC IGBTs, wherein an n-blocking region is provided in a transition section between a diode section and an IGBT section. Background Technology

[0002] Many functions of modern devices in automotive, consumer, and industrial applications—such as converting electrical energy and driving electric motors or generators—rely on power semiconductor switches. For example, insulated-gate bipolar transistors (IGBTs), metal-oxide-semiconductor field-effect transistors (MOSFETs), and diodes have been used in a variety of applications, including, but not limited to, switches in power supplies and power converters.

[0003] Power semiconductor devices typically include a semiconductor body configured to conduct positive load current along a load current path between two load terminals of the device.

[0004] Furthermore, in the case of controllable power semiconductor devices (e.g., transistors), the load current path can be controlled by means of an insulating electrode, typically referred to as the gate electrode. For example, when a corresponding control signal is received from, for example, a driver unit, the control electrode can set the power semiconductor device to one of an on state and an off state. In some cases, the gate electrode can be included within a trench of the power semiconductor switch, wherein the trench can be, for example, arranged in a strip-like or needle-like configuration.

[0005] Some power semiconductor devices further provide reverse conduction; during the reverse conduction state, the power semiconductor device conducts reverse load current. Such devices can be designed so that the forward load current capability (in magnitude) is substantially the same as the reverse load current capability.

[0006] A typical device providing both forward and reverse load current capabilities is the reverse-conducting (RC) IGBT, whose general configuration is known to those skilled in the art. Typically, for an RC IGBT, the forward conduction state is controllable by providing a corresponding signal to the gate electrode, while the reverse conduction state is typically not controllable, but rather occurs due to the corresponding diode structure in the RC IGBT, where the RC IGBT exhibits reverse conduction if a reverse voltage is present at the load terminals.

[0007] The desired solution is to provide an RC IGBT that, in addition to its high efficiency in power loss, also offers high controllability and robustness. Summary of the Invention

[0008] The aspects described herein relate to embodiments of RC IGBTs and embodiments of methods for forming RC IGBTs, wherein an n-blocking region is provided in the transition section between the diode section and the IGBT section. Exemplary configurations of the n-blocking region can allow for Qrr reduction, particularly when RC IGBTs are employed in drive applications requiring fast switching capability and short-circuit durability. For example, during a short circuit in the IGBT(s) section(s), the RC IGBT typically reaches its hottest point in the central region of the IGBT(s) section(s), while the diode(s) section(s) encounters no current and can cool the IGBT(s) section(s), thus improving the short-circuit durability of the RC IGBT. The greater the integration density of the diode, the greater the potential for improvement in the short-circuit durability of the IGBT. However, if the gate potential switches from the on-state value (e.g., 15V) to a value lower than the threshold voltage of the IGBT MOS structure (e.g., 0V, -8V, -15V) to avoid short-circuiting the DC link, strong diode integration can become a limitation in reducing power losses due to the strong increase in charge carrier quantity in the portion of the IGBT segment near the diode region before reverse recovery. Meanwhile, a fine pattern of the pn structure can be placed on the back side of the transition section, which suppresses charge carrier injection during the on-state and reverse recovery.

[0009] According to an embodiment, the RC IGBT includes: an active region having an IGBT segment, a diode segment, and a transition segment between the IGBT segment and the diode segment, wherein the IGBT segment and the diode segment are adjacent to the transition segment from opposite lateral directions; an edge termination region surrounding the active region; a semiconductor body having a front side and a back side, the thickness of the semiconductor body being defined as a distance along a vertical direction between the front side and the back side, wherein the total lateral extension of the transition segment reaches at least 30% of the thickness of the semiconductor body; a plurality of trenches disposed in each of the IGBT segment, the diode segment, and the transition segment, each trench extending vertically from the front side into the semiconductor body and including a trench electrode isolated from the semiconductor body by a trench insulator, wherein two adjacent trenches define a corresponding mesa portion in the semiconductor body; a first load terminal at the front side of the semiconductor body and a second load terminal at the back side of the semiconductor body. The IGBT segment is configured to conduct a forward load current between the first load terminal and the second load terminal. The diode segment is configured to conduct a reverse load current between the first load terminal and the second load terminal. The RC IGBT further includes a control terminal for controlling the forward load current, wherein the average density of trench electrodes electrically connected to the control terminal in the IGBT segment is at least twice the average density of trench electrodes connected to the control terminal in the transition segment. The RC IGBT further includes: a drift region of a first conductivity type formed in the semiconductor body and extending into each of the IGBT segment, diode segment, and transition segment; and a body region of a second conductivity type formed in a mesa portion of the semiconductor body and extending into each of the IGBT segment, diode segment, and transition segment. At least a portion of the body region is electrically connected to a first load terminal, wherein at least in the transition segment, the body region forms a pn junction with respect to a sub-segment of the mesa portion of the first conductivity type. At least in the transition segment, a blocking region having a first conductivity having a peak dopant concentration at least 100 times greater than the average dopant concentration of the drift region is arranged at least in a portion of the mesa sub-segment. The average dopant dose in the mesa portion of the transition section is at least 1.2 times higher than the average dopant dose in the mesa portion of the diode section.

[0010] According to another embodiment, a method of forming an RC IGBT includes forming the following components: an active region having IGBT segments, diode segments, and a transition segment between the IGBT segments and the diode segments, wherein the IGBT segments and the diode segments are adjacent to the transition segment from opposite lateral directions; an edge termination region surrounding the active region; a semiconductor body having a front side and a back side, the thickness of the semiconductor body being defined as a distance along a vertical direction between the front side and the back side, wherein the total lateral extension of the transition segment reaches at least 30% of the thickness of the semiconductor body; a plurality of trenches arranged in each of the IGBT segments, diode segments, and the transition segment, each trench extending vertically from the front side into the semiconductor body and including a trench electrode isolated from the semiconductor body by a trench insulator, wherein two adjacent trenches define a corresponding mesa portion in the semiconductor body; a first load terminal at the front side of the semiconductor body and a second load terminal at the back side of the semiconductor body. The IGBT segments are configured to conduct a forward load current between the first load terminal and the second load terminal. The diode segment is configured to conduct reverse load current between a first load terminal and a second load terminal. The method further includes forming a control terminal for controlling a forward load current, wherein the average density of trench electrodes electrically connected to the control terminal in the IGBT segment is at least twice the average density of trench electrodes connected to the control terminal in the transition segment. The method further includes forming: a drift region of a first conductivity type, which is in the semiconductor body and extends into each of the IGBT segment, the diode segment, and the transition segment; and a body region of a second conductivity type, which is formed in a mesa portion of the semiconductor body and extends into each of the IGBT segment, the diode segment, and the transition segment. At least a portion of the body region is electrically connected to the first load terminal, wherein at least in the transition segment, the body region forms a pn junction with respect to a sub-segment of the mesa portion of the first conductivity type. The method further includes forming a first conductivity barrier region at least in the transition segment, having a peak dopant concentration at least 100 times larger than the average dopant concentration of the drift region and being disposed at least in a portion of the mesa sub-segment. The average dopant dose in the mesa portion of the transition section is at least 1.2 times higher than the average dopant dose in the mesa portion of the diode section.

[0011] Those skilled in the art will recognize the additional features and advantages upon reading the following detailed description and reviewing the accompanying drawings. Attached Figure Description

[0012] The components in the figures are not necessarily to scale; rather, the emphasis is on illustrating the principles of the invention. Furthermore, in each figure, the same reference numerals indicate corresponding components. In the figures:

[0013] Figure 1A simplified design of an RC IGBT according to one or more embodiments is illustrated schematically and exemplary.

[0014] Figure 2 The diagram schematically and exemplary illustrates a segment of the vertical cross-section of an IGBT segment of an RC IGBT according to some embodiments;

[0015] Figure 3 A section of the vertical cross-section of the diode section of an RC IGBT according to some embodiments is illustrated schematically and exemplary.

[0016] Figure 4 The illustration schematically and exemplaryly depicts some variations of one or more diode segments and one or more IGBT segments of an RC IGBT in their respective horizontal projections according to one or more embodiments.

[0017] Figure 5 The illustration schematically and exemplaryly depicts vertical cross-sections of different groove types that may be part of an RC IGBT according to one or more embodiments;

[0018] Figures 6 to 8 Each schematic and exemplary illustration depicts a segment of the vertical cross-section of an RC IGBT according to some embodiments;

[0019] Figures 9 to 11 Each schematic and exemplary illustration depicts a segment of the vertical cross-section and the associated segment of the horizontal projection of an RC IGBT according to some embodiments;

[0020] Figures 12 to 13 Both of these schematically and exemplary illustrate segments of the vertical cross-section of an RC IGBT according to some embodiments;

[0021] Figure 14 The diagram schematically and exemplaryly illustrates segments of vertical cross-sections of some exemplary configurations of the back side of an RC IGBT according to some embodiments;

[0022] Figure 15 A segment of the vertical cross-section of an RC IGBT according to one or more embodiments is illustrated schematically and exemplaryly.

[0023] Figure 16 The diagram schematically and exemplaryly illustrates segments of vertical cross-sections of some exemplary configurations of the back side of an RC IGBT according to some embodiments;

[0024] Figure 17 A segment of the vertical cross-section of an RC IGBT according to one or more embodiments is illustrated schematically and exemplaryly.

[0025] Figure 18 The illustration schematically and exemplaryly depicts segments of a vertical cross-section of some exemplary configurations on the back side of an RC IGBT according to some embodiments; and

[0026] Figures 19 to 21 Each schematic and exemplary illustration depicts a segment of the vertical cross-section of an RC IGBT according to some embodiments. Detailed Implementation

[0027] In the following detailed description, reference is made to the accompanying drawings, which form a part herein and illustrate by way of illustration specific embodiments in which the invention may be practiced.

[0028] In this regard, directional terms such as "top," "bottom," "below," "front," "back," "rear," "forward," "end," and "above" may be used with reference to the orientation of the figures described. Because the various parts of the embodiments may be positioned in many different orientations, directional terms are used for illustrative purposes and are by no means limiting. It is to be understood that other embodiments may be utilized and structural or logical changes may be made without departing from the scope of the invention. Therefore, the following detailed description is not intended to be limiting, and the scope of the invention is defined by the appended claims.

[0029] Reference will now be made in detail to various embodiments, with one or more examples of various embodiments illustrated in the figures. Each example is provided by way of explanation and is not intended to be limiting of the invention. For example, features of a part illustrated or described as an embodiment may be used in or in combination with other embodiments to produce yet another further embodiment. It is intended that the invention include such modifications and variations. Examples are described using specific language, which should not be construed as limiting the scope of the appended claims. The drawings are not to scale and are for illustrative purposes only. For clarity, unless otherwise stated, the same reference numerals have been used to designate the same elements or manufacturing steps in different drawings.

[0030] As used in this specification, the term "horizontal" is intended to describe an orientation of a horizontal surface that is substantially parallel to a semiconductor substrate or semiconductor structure. This can be, for example, the surface of a semiconductor wafer, die, or chip. For example, both the first lateral direction X and the second lateral direction Y mentioned below can be horizontal directions, wherein the first lateral direction X and the second lateral direction Y can be perpendicular to each other.

[0031] As used herein, the term "vertical" is intended to describe an orientation that is substantially arranged perpendicular to the horizontal surface, i.e., parallel to the normal direction of the surface of the semiconductor wafer / chip / die. For example, the extension direction Z mentioned below can be an extension direction perpendicular to both the first lateral direction X and the second lateral direction Y. The extension direction Z is also referred to herein as "vertical direction Z".

[0032] In this specification, n-doping is referred to as "first conductivity type" and p-doping as "second conductivity type". Alternatively, the reverse doping relationship can be used, so that the first conductivity type can be p-doped and the second conductivity type can be n-doped.

[0033] In the context of this specification, the terms "in ohmic contact," "in electrical contact," "in ohmic connection," and "electrical connection" are intended to describe a low-ohmic electrical connection or low-ohmic current path between two regions, segments, zones, portions, or components of a semiconductor device, or between different terminals of one or more devices, or between a terminal or metallization or electrode and a portion or component of a semiconductor device. Further, in the context of this specification, the term "contact" is intended to describe a direct physical connection between two elements of a respective semiconductor device; for example, a transition between two elements in contact with each other may not include further intermediate elements, etc.

[0034] Furthermore, in the context of this specification, unless otherwise stated, the term "electrically insulated" is used in its generally valid understanding and is therefore intended to describe two or more components that are positioned separately from each other and where there is no ohmic connection connecting those components. However, components that are electrically insulated from each other can still be coupled to each other, for example, by mechanical coupling and / or capacitive coupling and / or inductive coupling. For example, the two electrodes of a capacitor can be electrically insulated from each other and simultaneously mechanically and capacitively coupled to each other, for example, by means of an insulator such as a dielectric.

[0035] The specific embodiments described in this specification relate to, but are not limited to, RC IGBTs presenting a strip-like cell configuration, such as RC IGBTs that can be used in power converters or power supplies. Therefore, in embodiments, such RC IGBTs can be configured to carry load current to be fed to a load and / or corresponding load current supplied by a power source. For example, an RCIGBT may include multiple power semiconductor cells, such as monolithically integrated diode cells, derivatives of monolithically integrated diode cells, monolithically integrated IGBT cells, and / or derivatives thereof. Such diode / transistor cells can be integrated in a power semiconductor module. Multiple such cells can constitute a cell field region with an active region on which RC IGBTs are arranged.

[0036] As used herein, the term "RC IGBT" is intended to describe an RC IGBT on a single chip with high voltage blocking capability and / or high current carrying capability. In other words, embodiments of the RC IGBT described herein are single-chip RC IGBTs configured for high current (typically in the ampere range, such as several amperes or tens or hundreds of amperes) and / or high voltage (typically 100V and above, such as at least 400V or even higher, such as at least 3kV or even 10kV or higher).

[0037] For example, the RC IGBT described below can be a single-chip RC IGBT that is presented in a strip cell configuration and is configured to be used as a power component in low, medium, and / or high voltage applications. Several single-chip RC IGBTs can be integrated into a module to form an RC IGBT module, for example, for installation and use in low, medium, and / or high voltage applications such as major household appliances, general drives, electric drive systems, servo drives, traction, higher power transmission facilities, etc.

[0038] For example, the term "RC IGBT" as used in this specification is not directed at logic semiconductor devices used for, for example, storing data, computing data, and / or other types of semiconductor-based data processing.

[0039] Figure 1 An RC IGBT 1 according to one or more embodiments is illustrated schematically and exemplary in a simplified manner. To describe the configuration of the RC IGBT 1, reference will also be made below. Figures 2 to 4 .

[0040] RC IGBT 1 includes an active region 1-2, which has an IGBT segment 1-21, a diode segment 1-22, and a transition segment 1-23 between the IGBT segment 1-21 and the diode segment 1-22. The IGBT segment 1-21 and the diode segment 1-22 are adjacent to the transition segment 1-23 from opposite lateral directions (e.g., the diode segment 1-22 is along a first lateral direction X and the IGBT segment 1-21 is opposite to the first lateral direction X). As in Figure 4 As shown in the diagram, RC IGBT 1 may include multiple IGBT segments 1-21 that are substantially equivalently configured, multiple diode segments 1-22 that are substantially equivalently configured, and multiple transition segments 1-23 that are substantially equivalently configured. The different segments 1-21, 1-22, and 1-23 may be laterally distributed within the active region 1-2. Figure 4 The diagram illustrates several illustrative examples. For instance, active region 1-2 consists of segments 1-21, 1-22, and 1-23.

[0041] according to Figure 4 In variant (A), an IGBT segment 1-21 is centrally located in the active region 1-2, with two transition segments 1-23 and two diode segments 1-22 positioned to the left and right (with respect to the first lateral direction X). According to... Figure 4 In variant (B), a diode segment 1-22 is centrally located in the active region 1-2, while two transition segments 1-23 and two IGBT segments 1-21 are located on the left and right sides (with respect to the first lateral direction X). According to... Figure 4 The variant (C) includes multiple IGBT segments 1-21, multiple diode segments 1-22, and multiple transition segments 1-23 provided in the active region 1-2. Of course, the active region 1-2 can also contain... Figure 4 (C) shows more segments 1-23, 1-22, and / or 1-21 compared to the diagram. According to Figure 4 The variant (D) has a diode segment 1-22 arranged in the center in the active region 1-2, a frame-like transition segment 1-23 surrounding the diode segment 1-22 and an IGBT segment 1-21 surrounding the transition segment 1-23.

[0042] Regardless of the selected lateral spatial distribution of the IGBT segments 1-21, diode segments 1-22, and corresponding transition segments, it can be ensured that, with respect to the volume of the active region 1-2, the ratio between (one or more) IGBT segments 1-21 and (one or more) diode segments 1-22 is at least 1:1, or correspondingly at least 2:1, i.e., greater than or equal to 2:1. The selected ratio may depend on the application in which RC IGBTs are used. In an embodiment, at least 50% of the total volume of the active region 1-2 may be occupied for forming (one or more) IGBT segments, and the remaining 50% (or a lower percentage share) of the active region 1-2 may be used for forming (one or more) diode segments 1-22 and (one or more) transition segments 1-23. Regardless of the selected lateral spatial distribution of IGBT segments 1-21, diode segments 1-22, and corresponding transition segments, it can be ensured that the ratio between (one or more) IGBT segments 1-21 and (one or more) diode segments 1-22 is even greater than 3:1 with respect to the volume of the active region 1-2.

[0043] The following references will be made to "Diode Segment 1-22", "IGBT Segment 1-21", and "Transition Segment 1-23". It will be understood that the explanations provided below regarding these segments 1-21, 1-22, and 1-23 can be applied to each segment 1-21, 1-22, or 1-23 provided in the active region 1-2, respectively. For example, if multiple IGBT segments 1-21 are provided, each IGBT segment 1-21 can be configured equivalently (wherein, for example, IGBT segments 1-21 may differ in total lateral extension or present the same total lateral extension). Therefore, if multiple diode segments 1-22 are provided, each diode segment 1-22 can be configured equivalently (wherein, for example, diode segments 1-22 may differ in total lateral extension or present the same total lateral extension). Therefore, if multiple transition segments 1-23 are provided, each transition segment 1-23 can be configured equivalently (where, for example, transition segments 1-23 may differ in total lateral extension or present the same total lateral extension).

[0044] Edge termination region 1-3 surrounds active region 1-2; therefore, edge termination region 1-3 is arranged outside active region 1-2. Edge termination region 1-3 is laterally terminated by edge 1-4. Edge 1-4 can form the chip edge of RC IGBT 1.

[0045] As used herein, both the terms "edge termination region" and "active region" are associated with their respective technical meanings typically used by those skilled in the art in the context of RCIGBTs. That is, the active region 1-2 is primarily configured for forward and reverse load current conduction and switching purposes, while the edge termination region 1-3 primarily fulfills functions related to reliable blocking capability, proper guidance of the electric field, and sometimes charge carrier discharge, and / or further functions related to the protection and proper termination of the active region 1-2.

[0046] This manual mainly covers the active regions 1-2.

[0047] Pay attention again Figure 1 The semiconductor body 10 of the RC IGBT 1 has a front side 110 and a back side 120. The front side 110 and the back side 120 may vertically terminate the semiconductor body 10. Therefore, the thickness d of the semiconductor body 10 is defined as the distance Z between the front side 110 and the back side 120 along the vertical direction. In the lateral direction, the semiconductor body 10 may be terminated by edges 1-4 (see...). Figure 4Furthermore, both the front side 110 and the back side 120 can extend laterally along both the first lateral direction X and the second lateral direction Y. For example, both the front side 110 and the back side 120 can form corresponding horizontal surfaces of the semiconductor body 10. The thickness d of the semiconductor body 10 can be, for example, the distance along the vertical direction Z between the front side 110 and the back side 120 measured at the center of the active regions 1-2.

[0048] The total lateral extension TLE of transition sections 1-23 reaches at least 30% of the semiconductor body thickness d. The TLE can also be greater than 30% of the thickness d, for example, greater than 0.5 × d, or even greater than 0.7 × d. The thickness d of the semiconductor body 10 depends on the desired blocking voltage capability of the RCIGBT 1. The thickness d can be, for example, in the range of 40 μm to 800 μm. Furthermore, the total lateral extension TLE of transition sections 1-23 can be substantially constant along the vertical extension Z of the transition sections 1-23 in the vertical direction Z from the front side 110 to the back side 120.

[0049] In the embodiment, the total lateral extension TLE1 of IGBT segments 1-21 reaches at least 50% of the semiconductor body thickness d. TLE1 may also be greater than 50% of the thickness d, for example, greater than 2×d, or even greater than 2.5×d, or even greater than 4×d.

[0050] In an embodiment, the total lateral extension TLE2 of diode segments 1-22 reaches at least 20% of the semiconductor body thickness d. TLE2 may also be greater than 30% of the thickness d, for example, greater than 0.5 × d, or even greater than d.

[0051] The first load terminal 11 is located on the front side 110 of the semiconductor body, and the second load terminal 12 is located on the back side 120 of the semiconductor body. IGBT segments 1-21 are configured to conduct forward load current between the first load terminal 11 and the second load terminal 12, for example, if the potential at the second load terminal 12 is greater than the potential at the first load terminal 11. Diode segments 1-22 are configured to conduct reverse load current between the first load terminal 11 and the second load terminal 12, for example, if the potential at the second load terminal 12 is lower than the potential at the first load terminal 11.

[0052] Therefore, in this embodiment, the diode segment 1-22 that conducts the reverse load current is spatially separated from the IGBT segment 1-21 that conducts the forward load current. Furthermore, in this embodiment, the diode segment 1-22 is independent of the control signal (e.g., the control signal provided to the control electrode 141 mentioned below). This means that the diode segment 1-22 can be configured such that it conducts the reverse load current once the potential at the second load terminal 12 (typical polarity) is lower than the potential at the first load terminal 11 (at least lower than the internal threshold voltage of the diode segment), regardless of the control signal provided to the IGBT segment 1-21.

[0053] The RC IGBT 1 further includes a control terminal 13 for controlling the forward load current. The control terminal 13 may also be located at the front side 110.

[0054] According to the terminology typically associated with RC IGBT, control terminal 13 may be a gate terminal, first load terminal 11 may be an emitter (source) terminal, and second load terminal 12 may be a collector (drain) terminal.

[0055] For example, the first load terminal 11 includes front-side metallization and / or the second load terminal 12 includes back-side metallization. For example, the first load terminal 11 is an emitter terminal, and the second load terminal 12 is a collector terminal. At the front side 110, the semiconductor body 10 may be connected to the front-side metallization. At the back side 120, the semiconductor body 10 may be connected to the back-side metallization.

[0056] In an embodiment, the first load terminal 11 (e.g., the front-side metallization) overlaps with the active region 1-2 laterally, i.e., along a first lateral direction X and / or a second lateral direction Y and / or a combination thereof. It should be noted that the first load terminal 11 can be structured laterally, for example, to establish a local contact with the semiconductor body 10 at the front side 110. For example, as in... Figure 2 and Figure 3 As illustrated in the exemplary diagram, the partial contact can be established by means of a contact plug 111 that penetrates the insulating structure 13 to contact the table portion 17.

[0057] Similarly, in embodiments, the second load terminal 12 (e.g., the back-side metallization) overlaps laterally with the active regions 1-2, i.e., along the first lateral direction X and / or the second lateral direction Y and / or a combination thereof. It should be noted that the second load terminal 12 is typically not structured, but rather formed uniformly and monolithically on the back side 120 of the semiconductor body, for example, to establish a uniform lateral contact (i.e., a continuous contact surface) with the semiconductor body 10 on the back side 120. Such a uniform structure can also be implemented in regions where the second load terminal 12 overlaps laterally with the edge termination regions 1-3.

[0058] For example, the lateral boundary of the active region 1-2 is defined by the lateral boundary of the outermost power unit(s) of diode segment(s) 1-23 and / or IGBT segment(s) 1-21. Therefore, the lateral boundary of the active region 1-2 can be defined at the front side 110. This lateral boundary can be defined by the outermost source region(s) 101 (see the explanation below in more detail). For example, all functional elements capable of conducting forward and reverse load currents appear in the vertical projection of the active region 1-2 of the RC IGBT 1, including at least the first load terminal 11 (e.g., its front metal contact, such as one or more of contact plugs 111), the source region(s) 101, the body region 102, the drift region 100, the IGBT emitter region 103, the diode cathode region 104, and the second load terminal 12 (e.g., its back metal), as will be explained in more detail below.

[0059] In an embodiment, the edge termination region 1-3 and the active region 1-2 may be arranged substantially symmetrically to each other about the central vertical axis of the RC IGBT 1, for example.

[0060] Furthermore, according to an embodiment, the lateral transition between the active region 1-2 and the edge termination region 1-3 can extend exclusively along the vertical direction Z. As explained above, the lateral boundary of the active region 1-2 can be defined at the front side 110, and thus the vertical projection of such defined lateral boundary along the vertical direction Z can be observed at the back side 120, wherein the second load terminal 12 at the back side 120 is, for example, not structured laterally but uniformly formed.

[0061] Still referencing Figure 5 and Figure 6Multiple trenches 14, 15, 16 are arranged in each of the IGBT sections 1-21, diode sections 1-22, and transition sections 1-23. Each trench 14, 15, 16 extends from the front side 110 into the semiconductor body 10 along the vertical direction Z and includes a corresponding trench electrode 141, 151, 161 isolated from the semiconductor body 10 by a corresponding trench insulator 142, 152, 162. Two adjacent trenches define a corresponding mesa portion 17 in the semiconductor body 10.

[0062] Each trench 14, 15, 16 can have a strip-like configuration, for example, as shown in... Figure 9 As best illustrated in one of the horizontal projections in (B), this means that the corresponding trench length (e.g., along the second lateral direction Y) is much larger than the corresponding trench width (e.g., along the first lateral direction X).

[0063] As will be further explained below, different types of trenches can be provided in sections 1-21, 1-22, and 1-23. A first type of trench can be a control trench 14, whose trench electrode 141 is electrically connected to the control terminal 13 and is therefore referred to as control electrode 141. A second type of trench can be a source trench 16, whose trench electrode 161 is electrically connected to the first load terminal 11 and is therefore referred to as source electrode 161. A third type of trench can be another trench 15, whose trench electrode 151 is neither electrically connected to the first load terminal 11 nor electrically connected to the control terminal 13. For example, in one embodiment, trench 15 is a floating trench, and trench electrode 151 is not connected to a defined potential but is electrically floating. For example, in another embodiment, trench 15 is a dummy trench, and trench electrode 151 is electrically connected to the control terminal 13 but does not directly control the conduction of the forward load current because an unconnected source region 101 (connected to the first load terminal) is arranged adjacent to trench 15. In another embodiment, the trench electrode 151 is connected to a potential different from that of the control terminal 13 and different from that of the first load terminal 11.

[0064] Each trench type can have equal dimensions in terms of width (along the first lateral direction X), depth (along the vertical direction Z, for example, the distance from the front side 110 down to the bottom of the trench), and / or length (along the second lateral direction Y).

[0065] IGBT sections 1-21 may include multiple IGBT cells, each IGBT cell having a specific trench pattern, i.e., a lateral sequence of trenches of a specific type, such as one or more control trenches 14, zero or more source trenches 16, and zero or more other trenches 15. Similarly, diode sections 1-22 may include multiple diode cells, each diode cell having a specific trench pattern, i.e., a lateral sequence of trenches of a specific type, such as one or more source trenches 16, zero or more other trenches 15, and zero or more control trenches 14.

[0066] As indicated above, trenches 14, 15, and 16 are arranged together with each of the diode sections 1-22, IGBT sections 1-21, and transition sections 1-23. In one embodiment, trenches 14, 15, and 16 in each of the IGBT sections 1-21, diode sections 1-22, and transition sections 1-23 are arranged one after another in the lateral direction with the same lateral trench spacing; that is, the lateral trench spacing (i.e., the distance between two adjacent trenches) does not change between sections 1-21, 1-22, and 1-23. The lateral trench spacing may define a lateral distance between two adjacent trenches not exceeding 1 / 30 of the semiconductor body thickness d. In other words, the lateral width of the mesa portion 17 in each of the diode sections 1-22, IGBT sections 1-21, and transition sections 1-23 may be the same as each other.

[0067] Additionally, each of trenches 14, 15, and 16 may have the same trench depth (total vertical extension). For example, the lateral trench spacing may define a lateral distance between two adjacent trenches of no more than 50% or 30% of the trench depth.

[0068] In an embodiment, the lateral trench spacing can define a lateral distance of no more than 10 μm, no more than 5 μm, or no more than 1 μm between two adjacent trenches. For example, adjacent trenches are thus displaced from each other by no more than 1 μm in the lateral direction.

[0069] Therefore, the width of each countertop portion 17 is within the range defined by the spacing of the transverse grooves.

[0070] Now, additional reference Figure 6In IGBT sections 1-21, the average density of the trench electrodes 141 electrically connected to the control terminal 13, i.e., the average density of the control electrodes 141, is at least twice the average density of the control electrodes 141 (connected to the control terminal 13) in transition sections 1-23. The difference in control electrode density can even be greater than two times, for example, greater than three or four times. It is even possible that in embodiments with floating trench electrodes 151, the trench electrodes 141 are not provided in transition sections 1-23, and only the source trench 16 and / or other trenches 15 are present.

[0071] As explained above, the lateral trench spacing can be the same for all sections 1-21, 1-22, and 1-23. This means that the average density of the trench electrodes can also be the same for all sections 1-21, 1-22, and 1-23. However, as indicated above, the trench pattern—e.g., the arrangement of different types of trenches—can vary between sections 1-21, 1-22, and 1-23. One variation is that the density of the control electrode 141 in IGBT section 1-21 is at least twice as high as the density of the control electrode 141 in transition sections 1-23 (which can even reach zero).

[0072] As used herein, the term "density" refers to the number of control electrodes 141 (or dummy electrodes 151 also connected to control terminal 13) divided by the total number of trench electrodes present in the respective sections 1-21, 1-22 or correspondingly in 1-23.

[0073] In the illustrative example, the total number of trench electrodes in IGBT sections 1-21 is 120, and 40 trench electrodes are control electrodes 141, resulting in a control electrode density of 30%. For example, the total number of trench electrodes in transition sections 1-23 is 30, and 3 trench electrodes are control electrodes 141, resulting in a control electrode density of 10%.

[0074] Therefore, in one embodiment, each of the trenches 15, 16 extending into the transition sections 1-23 is electrically floated or electrically connected to a potential different from that of the control terminal 13, thus resulting in a 0% control trench density. In another embodiment, at least 80% of each of the trenches 14, 15, 16 extending into the transition sections 1-23 is electrically floated or electrically connected to a potential different from that of the control terminal 13, and wherein at least one of the remaining 20% ​​of the trenches 14 extending into the transition sections 1-23 is electrically connected to the control terminal 13 for forming at least one local IGBT cell in the transition sections 1-23. This aspect will be described in further detail below.

[0075] Back Figure 2 , Figure 3 and Figure 6 The RC IGBT 1 further includes a drift region 100 of a first conductivity type, which is formed in the semiconductor body 10 and extends into each of the IGBT segments 1-21, diode segments 1-22 and transition segments 1-23.

[0076] A body region 102 of a second conductivity type is formed in the mesa portion 17 of the semiconductor body 10 and extends into each of the IGBT segments 1-21, diode segments 1-22, and transition segments 1-23. At least a portion of the body region 102 is electrically connected to the first load terminal 11. At least in the transition segments 1-23, the body region 102 forms a pn junction with respect to a sub-segment of the mesa portion 17 of the first conductivity type. For example, as will be described below and as shown in the figures (e.g.) Figure 6 As illustrated in the figure, in this embodiment, not a corresponding portion of the body region 102 in each tabletop portion 17 is electrically connected to the first load terminal 11.

[0077] A source region 101 of a first conductivity type is also disposed at the front side 110 and electrically connected to the first load terminal 11. The source region 101 is provided, for example, only partially in the IGBT sections 1-21 and does not extend into the diode sections 1-22. However, according to some embodiments, some source regions 101 may also be provided partially in the transition sections 1-23. In other embodiments, the source regions are present neither in the diode sections 1-22 nor in the transition sections 1-23.

[0078] The body region 102 can be arranged to make electrical contact with the first load terminal 11, for example, by means of a contact plug 111. In each IGBT cell of IGBT segments 1-21, at least one source region 101 of a first conductivity type can be further provided, which is also arranged to make electrical contact with the first load terminal 11, for example, by means of a contact plug 111. The main portion of the semiconductor body 10 is formed as a drift region 100 of a first conductivity type, which can be connected to the body region 102 and form a pn junction therewith. The body region 102 isolates the source region 101 from the drift region 100.

[0079] Upon receiving a corresponding control signal, for example, from a gate driver unit (not shown), each control electrode 141 can induce an inversion channel in a segment of the body region 102 adjacent to the corresponding control electrode 141. Therefore, each of the plurality of IGBT units can be configured to conduct at least a portion of the forward load current between the first load terminal 11 and the second load terminal.

[0080] The basic configuration of the IGBT cells in IGBT sections 1-21 of RC IGBT 1 described above is as known to those skilled in the art, and the term "IGBT cell" is used in this specification within the scope of the technical meaning typically associated therewith by those skilled in the art.

[0081] In one embodiment, the drift region 100 extends along the vertical direction Z until it contacts the field stop layer 108, which is also of the first conductivity type but exhibits a higher dopant dose compared to the drift region 100. The field stop layer 108 typically has a significantly smaller thickness compared to the drift region 100.

[0082] The drift region 100 or the field stop layer 108 (if present) extends along the vertical direction Z until it connects with the IGBT emitter region 103 of IGBT segment 1-21, the diode cathode region 104 of diode segment 1-22, or the doped region 109 of transition segment 1-23 (see [link]). Figure 14 ).

[0083] The diode cathode region 104 is of the first conductivity type and is electrically connected to the second load terminal 12, and is coupled to the drift region 100, for example, by means of the field stop layer 108.

[0084] The IGBT emitter region 103 is of the second conductivity type and is electrically connected to the second load terminal 12, and is coupled to the drift region 100, for example, by means of the field stop layer 108.

[0085] Each of the IGBT emitter region 103 in IGBT section 1-21, the diode cathode region 104 in diode section 1-22, and the doped region 109 in transition section 1-23 can be arranged to make electrical contact with the second load terminal 12.

[0086] Further optional aspects of the IGBT emitter region 103 of IGBT sections 1-21, the diode cathode region 104 of diode sections 1-22, and the doped region 109 of transition sections 1-23 will be described below.

[0087] In general, the IGBT emitter region 103 can act as an emitter of the second conductivity type. Furthermore, although the device is implemented as an RC IGBT 1, the IGBT emitter region 103 in some embodiments does not include any segment of the first conductivity type, exhibiting a fairly high dopant concentration, typically in the range of 10⁻⁶. 16 cm -3 Up to 10 20 cm -3 Within the range; conversely, according to some embodiments, the diode cathode region 104 is exclusively formed in the diode segments 1-22.

[0088] In this embodiment, the dopant concentration in the drift region 100 can be 10. 12 cm -3 Up to 10 14 cm -3 Within the range.

[0089] In this embodiment, the dopant concentration of each source region 101 can be 10. 19 cm -3 Up to 10 21 cm -3 Within the range.

[0090] In an embodiment, the dopant concentration of each body region 102 can be 10. 16 cm -3 Up to 10 18 cm -3 Within the range.

[0091] In this embodiment, the dopant concentration of the field stop layer 108 can be 10. 14 cm -3 Up to 3×10 16 cm -3 Within the range.

[0092] In this embodiment, the dopant concentration of the IGBT emitter region 103 can be 10. 16 cm -3 Up to 10 18 cm -3 Within a certain range. However, in the embodiments, the dopant concentration can vary along the lateral extension of the IGBT emitter region 103.

[0093] In this embodiment, the dopant concentration in the diode cathode region 104 can be 10. 19 cm -3 Up to 10 21 cm -3 Within a certain range. However, in embodiments, the dopant concentration can vary along the lateral extension of the diode cathode region 104 (and even change the polarity).

[0094] It should be noted that, Figures 2 to 3 The groove pattern shown in the illustration is merely exemplary; regarding Figures 6 to 21 Describe other groove patterns.

[0095] In this embodiment, diode segments 1-22 are not equipped with a source region 101; for example, there is no doped semiconductor region of the first conductivity type electrically connected to the first load terminal in diode segments 1-22. Instead, in order to form a diode configuration in diode segments 1-22 for conducting reverse load current, only the body region 102 is electrically connected to the first load terminal 11, wherein the body region 102 forms a pn junction with, for example, a drift region 100 (or a further blocking region 105, if present), and there is a semiconductor path of only the first conductivity type along the vertical direction Z toward the second load terminal 12, which is not interrupted by any further regions of the second conductivity type.

[0096] As explained above, in contrast to diode segments 1-22, according to the embodiment, IGBT segments 1-21 include at least one IGBT cell, wherein a segment of source region 101 is connected to the first load terminal 11 and arranged adjacent to one of the control trenches 14 and isolated from drift region 100 (or another further blocking region 106, if present) by body region 102. For example, the lateral boundary of IGBT segments 1-21 is defined by the lateral boundary of the outermost(one or more) IGBT cell(s). Therefore, the lateral boundary of IGBT segments 1-21 can be defined at the front side 110. This lateral boundary can be defined by the outermost(one or more) source region(s) 101. For example, all functional elements capable of conducting positive load current appear in the vertical projection of IGBT segments 1-21 of the RC IGBT 1, including at least a first load terminal 11 (e.g., its front metal contact, such as one or more of contact plugs 111), one or more source regions 101, body region 102, drift region 100, IGBT emitter region 103, and a second load terminal 12 (e.g., its back metal). Furthermore, these functional elements may extend along the overall lateral extension TLE1 of the IGBT segments 1-21.

[0097] Now refer to more details Figure 6 At least in transition sections 1-23, a barrier region 107 having a peak dopant concentration at least 100 times greater than the average dopant concentration of drift region 100 is arranged at least in the portion of the mesa portion that is in contact with the body region 102. The average dopant dose of the mesa portion in transition sections 1-23 is at least 1.2 times higher than the average dopant dose of the mesa portion in diode sections 1-22.

[0098] Here it should be noted that both of the dopant dosages mentioned in the preceding paragraphs are related to the dopant concentration of the dopant for the first conductivity type; for example, as with regard to Figure 21As explained in more detail, the body region 102 in the diode segments 1-22 may extend even below the bottom of the trench, such that some or all of the mesa portions 17 in the diode segments 1-22 are of the second conductivity type (where an average dopant dose that is substantially zero in relation to the dopant concentration of the dopant of the first conductivity type is generated).

[0099] The peak dopant concentration in barrier region 107 can reach at least 1×10⁻⁶. 15 cm -3 , reaching at least 2×10 16 cm -3 Or reach or even exceed 5×10 17 cm -3 .

[0100] As indicated above, the average dopant concentration in drift region 100 can be 1 × 10⁻⁶. 12 cm -3 Up to 1×10 14 cm -3 Within a certain range. For example, the average dopant concentration of drift region 100 is determined in the section of drift region 100 below the bottom of the trench.

[0101] The average dopant dose of the mesa portion in transition sections 1-23 can reach at least 1×10⁻⁶. 12 cm -2 , reaching at least 5×10 12 cm -2 Or reach or even exceed 2×10 13 cm -2 As explained, this average dopant dose can be achieved by means of the blocking region 107 extending into these mesa sub-sections of the transition sections 1-23.

[0102] The average dopant dose of the mesa portion in diode segments 1-22 can be 5 × 10⁻⁶. 11 cm -2 Up to 2×10 13 cm -2 Within a certain range, for example, reaching 4×10 13 cm -2 As will be explained, this average dopant dose can be achieved by means of further blocking regions 105 and / or drift regions extending into these mesa sub-portions in diode segments 1-22.

[0103] The average dopant dose in the mesa portion of IGBT segments 1-21 can be 5 × 10⁻⁶. 11 cm -2 Up to 2×10 13 cm -2Within a certain range, for example, reaching 4×10 13 cm -2 As will be explained, this average dopant dose can be achieved by means of another further blocking region 106 and / or drift region extending into these mesa sub-sections of IGBT segments 1-21.

[0104] Therefore, the average dopant dose of the mesa portion in transition sections 1-23 is at least 1.2 times higher than the average dopant dose of the mesa portion in diode sections 1-22. The average dopant dose of the mesa portion in transition sections 1-23 can be at least 1.5 times higher or at least twice higher than the average dopant dose of the mesa portion in diode sections 1-22. Optionally, the average dopant dose of the mesa portion in IGBT sections 1-21 can be up to 5 / 6 times higher than the average dopant dose of the mesa portion in transition sections 1-23. The average dopant dose of the mesa portion in IGBT sections 1-21 can be up to 2 / 3 times or up to 1 / 2 times higher than the average dopant dose of the mesa portion in transition sections 1-23.

[0105] The mesa sub-parts in the mesa portions 17 of sections 1-21, 1-22 and 1-23 can therefore be formed by a drift region 100 extending into the mesa portion 17, or additionally or alternatively formed by a blocking region 107 extending into the mesa portion 17 of the transition sections 1-23, or correspondingly, as will be explained in more detail below, a further blocking region 105 extending into the mesa portion 17 of the diode sections 1-22, or correspondingly, as will be explained in more detail below, another further blocking region 106 extending into the mesa portion 17 of the IGBT sections 1-21.

[0106] Therefore, in the embodiments, regarding the dopant of the first conductivity type, the average dopant dose of the mesa portion forming a pn junction with the body region 102 within the transition section 1-23 can be the highest compared to the corresponding mesa portions of the IGBT sections 1-21 and the diode sections 1-22. Simultaneously, the density of the control electrode 141 present in the IGBT sections 1-21 is greater than the density of the control electrode 141 present in the transition section 1-23 (which can even be zero).

[0107] For example, mentioned here Dopant dosage Each of them is defined by the dopant concentration integraled along the vertical direction Z (which points from the first load terminal 11 to the second load terminal 12).

[0108] Furthermore, as mentioned here Average dopant doseEach of these can be defined as an average dopant dose taken along a distance of at least 5 μm or at least 10 μm in at least one of the lateral directions X / Y perpendicular to the vertical direction Z. The corresponding average dopant dose can even be defined by taking the average dopant dose taken along the total lateral extension of the corresponding region (or correspondingly, the corresponding volume) in the lateral directions X / Y. For example, for comparative purposes, the average dopant dose of the mesa sub-regions in transition sections 1-23 is determined at the same vertical level and along the same lateral distance as the average dopant dose of the mesa sub-regions in diode sections 1-22.

[0109] For example, the dopant dose of the mesa portion in transition sections 1-23 is determined by integrating the dopant concentration down the horizontal distance from the pn junction at body region 102 to the bottom of the trench in the corresponding mesa portion. Therefore, in this example, the dopant dose of the mesa portion in diode sections 1-22 is determined by integrating the dopant concentration down the horizontal distance from the pn junction at body region 102 to the bottom of the trench in the corresponding mesa portion. Furthermore, in this example, the average dopant dose of the mesa portion in transition sections 1-23 is the average dopant dose of the total lateral extension TLE along the first lateral direction X of transition sections 1-23, and the average dopant dose of the mesa portion in diode sections 1-22 is the average dopant dose of the total lateral extension TLE2 along the first lateral direction X of diode sections 1-22.

[0110] Furthermore, the term " average "Dopant dose" refers to an electrically active dopant of the same conductivity type. Therefore, changes in the average dopant dose can also be achieved by keeping the dose of one dopant type constant in both parts and by applying anti-doping and / or damage doping. In addition, differences in (net) average dopant doses can be achieved by such means.

[0111] Furthermore, it should be understood that the integral path used to determine the average dopant dose does not extend beyond the boundary of the relevant semiconductor portion.

[0112] In embodiments, at least a portion of the body region 102 in IGBT segments 1-21 is coupled to the drift region 100 without the blocking region 107, and / or at least a portion of the body region 102 in diode segments 1-22 is coupled to the drift region 100 without the blocking region 107. For example, in one embodiment, the body region 102 in both IGBT segments 1-21 and diode segments 1-22 is directly coupled to the relatively weakly doped drift region 100, as in... Figure 6As shown in the diagram. In this embodiment, the mesa portion 17 of the IGBT sections 1-21 and the diode sections 1-22 does not have a blocking region of the first conductivity type.

[0113] The total lateral extension of the blocking region 107 in the transition section 1-23 can be the same as the total lateral extension TLE of the transition section 1-23, wherein, of course, the blocking region 107 is repeatedly transversely interrupted by the grooves 15 / 16 of the transition section 1-23.

[0114] For example, the trenches in diode sections 1-22 and transition sections 1-23 are source trenches 16 or floating trenches 15. Furthermore, each mesa portion in diode sections 1-22 and transition sections 1-23 can be electrically connected to the first load terminal 11, for example, by means of a contact plug 111.

[0115] In contrast, the trench type in IGBT sections 1-21 can vary; according to the illustrated embodiment, a successively repeating trench-mesa pattern corresponding to "kGkSoSoDoSoS" can be used to form the IGBT cell. Figure 6 The diagram illustrates one of these, where "k" represents the mesa portion 17 connected to the first load terminal 11, "o" represents the mesa portion 17 not connected to the first load terminal 11 (meaning the transition along the vertical Z direction between the first load terminal 11 and the mesa portion 17 is non-conductive), "G" represents the gate trench 14, "S" represents the source trench 16, and "D" represents the dummy trench 15 (which is the same as the gate trench arranged between the non-contact mesa portions 17). Of course, different trench-mesa patterns can be used in other embodiments.

[0116] In an embodiment, the average dopant dose of the barrier region 107 reaches at least 20% and no more than 500% of the average dopant dose of the body region 102 in the transition sections 1-23. Again, the corresponding average dopant dose can be the dopant dose averaged along the total lateral extension TLE of the transition sections 1-23. For example, according to these exemplary provisions, the average dopant dose of the barrier region 107 can be 1 × 10⁻⁶. 12 cm -2 Up to 5×10 12 cm -2 Within a certain range, for example, reaching 5×10 13 cm -2 For example, the average dopant dose of the bulk region 102 in transition sections 1-23 can be 5 × 10⁻⁶. 12 cm -2 Up to 2×10 13 cm -2Within a certain range, for example, reaching 5×10 13 cm -2 In this context, for example, the dopant dosage is determined adjacent to the trench sidewalls and excludes the highly doped contact area near the contact surface.

[0117] It should be noted here that the body region 102 in each of the diode sections 1-22, transition sections 1-23, and IGBT sections 1-21 can be configured equivalently. For example, the body region 102 is not laterally structured with respect to the diode sections 1-22, transition sections 1-23, and IGBT sections 1-21. Therefore, the average dopant dose of the body region 102 in the transition sections 1-23 indicated above can also exist in the diode sections 1-22 and in the IGBT sections 1-21.

[0118] In another embodiment, the configuration of the body region 102 is the same in the IGBT sections 1-21 and the transition sections 1-23, but it is different in the diode sections 1-22, as already mentioned above. Figure 21 As indicated. For example, there, the body region 102 is more heavily doped and / or extends deeper into the semiconductor body 10 along the vertical direction Z, for example, even deeper than the bottom of the trench in the diode sections 1-22.

[0119] In the embodiment, at least one of the average dopant dose of the mesa portion in IGBT segments 1-21, the average dopant dose of the mesa portion in diode segments 1-22, and the average dopant dose of the mesa portion in transition segments 1-23 is achieved by means of at least the lateral structure of the barrier layer including the barrier region 107 (each segment 1-21, 1-22, 1-23 is connected to the body region 102). For example, refer to... Figure 12Further blocking regions 105 can be arranged in diode segments 1-22, and yet another further blocking region 106 can be arranged in IGBT segments 1-21. Blocking regions 105, 106, and 107 can be generated within the same(one or more) processing steps, for example, by using a correspondingly structured mask during the implantation processing step; thus, the lateral structure of the blocking layer, or correspondingly the lateral structure of the mask used during the formation of the blocking layer, can ensure, for example, with respect to dopants of the first conductivity type, that the average dopant dose of the mesa portion forming a pn junction with the body region 102 in the transition segment 1-23 can be the highest compared to the corresponding mesa portions of IGBT segments 1-21 and diode segments 1-22. The mask used during the implantation step will then have a different ratio of opening area to mask area, so that a larger area of ​​the mesa portion in the transition segment 1-23 is implanted with dopants of the first conductivity type compared to that in diode segments 1-22 or IGBT segments 1-21. The average dopant dose of the mesa portion is then determined by obtaining the average dopant dose of the mesa portion including the blocking region 107 and the average dopant dose of the mesa portion excluding the blocking region 107. Meanwhile, as mentioned above, the density of the control electrode 141 appearing in IGBT segments 1-21 is greater than the density of the control electrode 141 appearing in transition segments 1-23 (which can even be zero). Furthermore, it should be understood that the average dopant dose of the mesa portions forming pn junctions with the body regions 102 of IGBT segments 1-21 and diode segments 1-22 can differ from each other, where, again, this difference can be achieved by using a correspondingly structured mask. Still referring to... Figure 12 It should be understood that the further blocking regions 105, 106 are optional and may be omitted in other embodiments (see [link]). Figure 6 In cases where the blocking region 107 (or a lighter-doped blocking region) does not extend into either the diode segment 1-22 or the latter of the IGBT segment 1-21, the mask used to form the blocking layer will thus completely block the diode segment 1-22 and the IGBT segment 1-21 from implantation.

[0120] In an embodiment, the RC IGBT 1 therefore includes a further blocking region 105 of first conductivity in diode segments 1-22, having a peak dopant concentration that is at least 10 times or even 100 times larger than the average dopant concentration of the drift region 100, and extending laterally along at least 10% of the total lateral extension TLE2 of the diode segments 1-22, wherein at least a portion of the body region 102 in the diode segments 1-22 is coupled to the drift region 100 at least by means of the further blocking region 105.

[0121] Additionally or alternatively, according to an embodiment, the RC IGBT 1 includes a further barrier region 106 of first conductivity in IGBT segments 1-21, having an average dopant concentration at least 10 times or even 100 times that of the average dopant concentration of the drift region 100, and extending laterally along at least 10% of the total lateral extension TLE1 of the IGBT segments 1-21, wherein at least a portion of the body region 102 in the IGBT segments 1-21 is coupled to the drift region 100 at least by means of the further barrier region 106.

[0122] The following describes exemplary aspects of a blocking layer that includes blocking region 107 and optional further blocking region 105 and yet another further blocking region 106.

[0123] For example, regarding alternative implementations of the barrier layer, see [reference]. Figure 7 .and Figure 6 Compared to the previous embodiment, the configurations of transition sections 1-23 and IGBT sections 1-21 remain unchanged. According to variations (A) and (B), a further blocking region 105 is provided in the diode sections 1-22, wherein forming this further blocking region 105 can be achieved by using a correspondingly structured mask during implantation, which is also employed to form blocking region 107 in transition sections 1-23. However, even with the presence of the further blocking region 105, it is ensured that the average dopant dose of the mesa sub-portions in transition sections 1-23 (which form a pn junction with the body region 102 in transition sections 1-23) is at least 1.2 times higher than the average dopant dose of the mesa sub-portions in diode sections 1-22 (which form a pn junction with the body region 102 in diode sections 1-22).

[0124] The average dopant dose in the further blocking region 105 can be 5 × 10⁵. 11 cm -2 Up to 2×10 13 cm -2 Within a certain range, for example, reaching 4×10 13 cm -2 The average dopant dose can also be the average dopant dose taken along the total lateral extension TLE2 of diode segments 1-22.

[0125] according to Figure 7 The variant (A) further implements a blocking region 105 in each mesa portion 17 of diode segments 1-22. Alternatively, according to Figure 7The variant (B) implements a further blocking region 105 only in a subset of the mesa portions 17 of the diode segments 1-22, for example, in only 20% to 80% of the mesa portions 17 of the diode segments 1-22. Therefore, the dopant doses for the corresponding individual mesa portions 17 in diode segments 1-22 and transition segments 1-23 can even be equal to each other; however, the average dopant dose of the further blocking regions 105 in diode segments 1-22 is lower than the correspondingly averaged dopant dose of the blocking regions in transition segments 1-23, thereby satisfying the following requirement: the average dopant dose of the mesa sub-portions in transition segments 1-23 (which form a pn junction with the body region 102 in transition segments 1-23) is at least 1.2 times higher than the average dopant dose of the mesa sub-portions in diode segments 1-22 (which form a pn junction with the body region 102 in diode segments 1-22).

[0126] Now refer to Figure 8 The embodiment shown in the figure, wherein... Figure 6 Compared to the previous embodiment, the configurations of diode sections 1-22 and IGBT sections 1-21 remain unchanged, and transition sections 1-23 include a plurality of (one in this example) local IGBT cells. However, the following provision is implemented: the average density of trench electrodes 141 electrically connected to the control terminal 13 in IGBT sections 1-21 is at least twice the average density of trench electrodes 141 connected to the control terminal 13 in transition sections 1-23. In this example, a gate trench 14 is provided in transition sections 1-23 together with the associated source region 101 in the adjacent mesa portion 17. In this embodiment, as also Figure 11 As illustrated in the diagram, the blocking region 107 in transition sections 1-23 can be structured laterally, for example, such that no lateral overlap is formed between the blocking region 107 and at least one local IGBT cell in transition sections 1-23. In another embodiment, the blocking region 107 in transition sections 1-23 is not structured but extends continuously within transition sections 1-23, for example, extending continuously without any alteration (as shown in...). Figure 9 (As illustrated in the exemplary diagram). Both embodiments can be utilized. Figure 8 The variant shown in the figure is used to implement this.

[0127] Now refer to Figure 9 The embodiment shown in the figure, wherein... Figure 8Compared to the previous embodiment, the configuration of diode segments 1-22 and transition segments 1-23 remains unchanged, and IGBT segments 1-21 are equipped with a further blocking region 106. Segment (A) illustrates a vertical cross-section, and segment (B) illustrates a corresponding horizontal projection of the same segment in this embodiment of the RC IGBT 1. According to this embodiment, a further blocking region 106 is provided in IGBT segments 1-21, wherein forming this further blocking region 106 can be achieved by means of a correspondingly structured mask used during the injection process that is also employed to form blocking region 107 in transition segments 1-23.

[0128] However, even with the presence of another further blocking region 106, it can be ensured that the average dopant dose of the mesa portion in transition sections 1-23 (which forms a pn junction with the body region 102 in transition sections 1-23) is at least 1.2 times higher than the average dopant dose of the mesa portion in IGBT sections 1-21 (which forms a pn junction with the body region 102 in IGBT sections 1-21). However, referring to... Figure 19 and Figure 20 —These two and Figures 9 to 11 The variations in the diagram illustrate a further change in the blocking region 106. It should be understood that it is not necessarily necessary to provide the latter's features. For example, the average dopant dose of the mesa portion in transition sections 1-23 (which forms a pn junction with the body region 102 in transition sections 1-23) can alternatively be substantially the same as the average dopant dose of the mesa portion in IGBT sections 1-21 (which forms a pn junction with the body region 102 in IGBT sections 1-21). In other words, the average dopant dose of the further blocking region 106 can be as large as the average dopant dose of the blocking region 107; for example, assuming that transition sections 1-23 do not include local IGBT cells (see...). Figure 19 That is, there is no control electrode 141 at all, or correspondingly, local IGBT cells are allowed in the transition sections 1-23 (see Figure 20 It is sufficient to ensure that the average density of the trench electrodes 141 electrically connected to the control terminal 13 is at least twice the average density of the trench electrodes 141 connected to the control terminal 13 in the transition sections 1-23.

[0129] Another further barrier region 106 can achieve an average dopant dose of 5 × 10⁶. 11 cm -2 Up to 2×10 13 cm -2 Within a certain range, for example, reaching 4×10 13 cm -2The average dopant dose can also be the average dopant dose taken along the total lateral extension TLE1 of IGBT segments 1-21.

[0130] according to Figure 9 A variant of this design implements a further blocking region 106 only in a subset of the mesa portion 17 of IGBT segments 1-21, for example, implementing a further blocking region 106 only in 30% of the mesa portion 17 of IGBT segments 1-21. Therefore, the dopant doses for the corresponding individual mesa portions 17 in IGBT segments 1-21 and transition segments 1-23 can even be equal to each other; however, averaging along the total lateral extension TLE1 of IGBT segments 1-21, the average dopant dose of the further blocking region 106 in IGBT segments 1-21 is lower than the correspondingly averaged dopant dose of the blocking region 107 in transition segments 1-23, thereby satisfying the optional requirement that the average dopant dose of the mesa sub-portion in transition segments 1-23 (which forms a pn junction with the body region 102 in transition segments 1-23) is at least 1.2 times higher than the average dopant dose of the mesa sub-portion in IGBT segments 1-21 (which forms a pn junction with the body region 102 in IGBT segments 1-21).

[0131] For example, if provided, another further blocking region 106 can laterally overlap with the source region 101 in IGBT segments 1-21, as in Figure 9 As shown in the diagram. Alternatively, such a structure for another further blocking region 106 can prevent overlap, as in... Figure 10 As shown in the diagram (apart from this difference, Figure 10 Diagram and Figure 9 (Same embodiment). Furthermore, the lateral structure achieved by means of the recess 1061 can again be formed by using a correspondingly structured mask during the formation of the barrier layer.

[0132] Now refer to Figure 11 The embodiment shown in the figure, wherein, with Figure 10Compared to the previous embodiment, the configurations of diode sections 1-22 and IGBT sections 1-21 remain unchanged. The blocking region 107 in the transition sections 1-23 can be structured laterally, as already indicated above, i.e., structured in a manner such that no lateral overlap is formed between the blocking region 107 and at least one local IGBT cell in the transition sections 1-23. This can be achieved through one or more corresponding recesses 1071 in the blocking region 107 that laterally overlap with the source region 101 of the local IGBT cell in the transition sections 1-23. However, even in this embodiment where the average dopant dose of the blocking region 107 is reduced due to at least one recess 1071, it can be ensured that the average dopant dose of the mesa portion in the transition sections 1-23 (which forms a pn junction with the body region 102 in the transition sections 1-23) is at least 1.2 times higher than the average dopant dose of the mesa portion in the IGBT sections 1-21 (which forms a pn junction with the body region 102 in the IGBT sections 1-21). For example, even if the local dopant dose of barrier region 107 and the local dopant dose of barrier region 106 are the same in both transition sections 1-23 and IGBT sections 1-21, such a difference in the average dopant dose (averaged along the total lateral extension TLE1 of IGBT sections 1-21 or correspondingly along the total lateral extension TLE of transition sections 1-23) can be achieved, for example, by an increased number and / or area of ​​recesses 1061 in a further barrier region 106 compared to the recesses 1071 of barrier region 107 in transition sections 1-23.

[0133] As indicated above, blocking region 107, and if present, further blocking region 105 and / or yet another further blocking region 106, can form a blocking layer for the RC IGBT 1. The blocking layer can be a continuous blocking layer, optionally provided with recesses 1071, 1061, for example, such that the vertical projection of the source region 101 in IGBT segments 1-21 and (if present) in transition segments 1-23 does not include blocking regions 106, 107.

[0134] Now refer to Figure 12 The embodiment shown in the figure is similar to... Figure 6Compared to the previous embodiment, the configurations of diode sections 1-22, IGBT sections 1-21, and transition sections 1-23 remain unchanged, except for the addition of a further blocking region 105 in diode sections 1-22 and a further blocking region 106 in IGBT sections 1-21. In this example, the further blocking regions 105 and 106, like blocking region 107 in transition sections 1-23, are not laterally structured; however, both the average dopant dose of blocking region 105 and the average dopant dose of blocking region 106 are equally lower than the average dopant dose of blocking region 107, for example, by half, such that the sum of the average dopant doses of blocking regions 105 and 106 is approximately as large as the average dopant dose of blocking region 107. For example, to achieve such a configuration, the same first injection can be applied to each of segments 1-21, 1-22, and 1-23, and an additional second injection is applied to transition segments 1-23 (but not to segments 1-22 and 1-21). Alternatively, to achieve such a configuration, the same first injection can be applied to both segments 1-21 and 1-23, and an additional second injection is applied to both segments 1-22 and 1-23 (but not to segment 1-21). Again, even if the blocking region is provided not only in the transition sections 1-23 but also in both the diode sections 1-22 and the IGBT sections 1-21, it can be ensured that: (a) the average dopant dose of the mesa portion in the transition section 1-23 (which forms a pn junction with the body region 102 in the transition section 1-23) is at least 1.2 times higher than the average dopant dose of the mesa portion in the diode sections 1-22 (which forms a pn junction with the body region 102 in the diode sections 1-22); and (b) the average dopant dose of the mesa portion in the transition section 1-23 (which forms a pn junction with the body region 102 in the transition section 1-23) is at least 1.2 times higher than the average dopant dose of the mesa portion in the IGBT sections 1-21 (which forms a pn junction with the body region 102 in the IGBT sections 1-21).

[0135] Based on such Figure 14 , Figure 16 and Figure 18 The corresponding segment of the horizontal projection shown in the figure is about Figures 13 to 20 This will be used to explain exemplary aspects of the doped regions 103, 104, and 109 in sections 1-21, 1-22, and 1-23. For illustrative purposes, in Figure 13 , Figure 15 and Figure 17 The associated sections of the vertical cross-section shown in the figure are respectively related to Figure 6The same. However, the optional modifications / variations of the design of sections 1-21, 1-22 and 1-23 at the front side 110 described above can also be implemented in combination with the modifications / variations at the rear side 120, which will now be described.

[0136] In some implementations, such as in Figure 14 , Figure 16 and Figure 18 As exemplarily illustrated in each of the variants, the IGBT emitter region 103 is doped with a dopant of a second conductivity type and does not include any portion of the first conductivity type. The doping can be uniform, or alternatively, as... Figure 18 As exemplarily illustrated in variations (A) and (B), the IGBT emitter region 103 is a laterally structured region having a plurality of highly doped IGBT emitter sub-regions 1031 electrically connected to the second load terminal 12 and coupled to the drift region 100, and a plurality of less doped IGBT emitter sub-regions 1032 electrically connected to the second load terminal 12 and coupled to the drift region 100. The difference in average dopant dose between sub-regions 1031 and 1032 can reach 10-fold or even 100-fold. This difference in average dopant dose between sub-regions 1031 and 1032 can allow for lower levels of hole injection during reverse recovery.

[0137] Furthermore, in some implementations, such as in Figure 14 (A) Figure 14 (B1) Figure 14 (B2) Figure 16 (Aa) and Figure 16 (B2a) and Figure 18 (A) and Figure 18 As illustrated in each of the variations of (B), the diode cathode region 104 may be entirely of the first conductivity type and electrically connected to the second load terminal 12 and coupled to the drift region 100. For example, in these implementations, the diode cathode region 104 is not structured but uniformly doped.

[0138] In other implementations, such as in Figure 14 (C) Figure 16 (Ab) and Figure 16 As exemplarily illustrated in each of the variations of (B2b), the diode cathode region 104 is laterally electrically connected to the second load terminal 12 and interrupted by one or more sub-regions 1041 of a second conductivity type coupled to the drift region 100. The sub-regions 1041 of the second conductivity type may constitute 50% of the total lateral extension of the diode cathode region 104 (which is the same as TLE2 described above), as in Figure 14 As shown in (C). In other implementations, such as in Figure 16 (Ab) and Figure 16 As shown in (B2b), the sub-region 1041 of the second conductivity type can be configured to be only significantly smaller than 50% of the total lateral extension of the diode cathode region 104, and is provided, for example, only near the transition sections 1-23. In terms of dopant dosage, the sub-region 1041 of the second conductivity can be configured in the same way as the IGBT emitter region 103. For example, providing the sub-region 1041 of the second conductivity as part of the diode cathode region 104 can allow hole injection during reverse recovery to prevent current snap-off.

[0139] Numerous variations can be used to form the doped regions 109 of the transition sections 1-23 at the back side 120. In some implementations, the configuration of the IGBT emitter region 103 can be simply extended into the transition sections 1-23 without modification. Therefore, in embodiments, the configuration of the doped regions 109 of the transition sections 1-23 is similar to that in... Figure 14 (A) Figure 14 (B) Figure 16 (Ab) and Figure 16 The configuration of the IGBT emitter region 103 shown in (B) is the same. Therefore, the doped region 109 can be of the second conductivity type, as with the IGBT emitter region 103, wherein either the IGBT emitter region 103 is a laterally structured region having the plurality of higher-doped IGBT emitter regions 1031 of the second conductivity type electrically connected to the second load terminal 12 and coupled to the drift region 100, and having the plurality of lower-doped IGBT emitter regions 1032 of the second conductivity type electrically connected to the second load terminal 12 and coupled to the drift region (100); and therefore, referring to Figure 18 (B) The doped region 109 is also a laterally structured region, having a plurality of highly doped sub-regions 1091 electrically connected to the second load terminal 12 and coupled to the drift region 100, and a plurality of less doped sub-regions 1092 electrically connected to the second load terminal 12 and coupled to the drift region 100. The difference in the average dopant dose between sub-regions 1091 and 1092 can correspond to those selected for the IGBT emitter region 103 and the diode cathode region 104. The difference in the average dopant dose between sub-regions 1091 and 1092 can allow for a strongly reduced electron injection in the diode on-state mode and very low hole injection during reverse recovery.

[0140] In other implementations, such as in Figure 14 (B1) Figure 14 (B2) and Figure 16 (B2a) Figure 16As shown in (B2b), the doped region 109 is not exclusively of the second conductivity type, but rather a mixed region having a plurality of first sub-regions 1091 of the first conductivity type electrically connected to the second load terminal 12 and coupled to the drift region 100, and a plurality of second sub-regions 1092 of the second conductivity type electrically connected to the second load terminal 12 and coupled to the drift region 100. The average dopant dose of each of the plurality of second sub-regions 1092 of the second conductivity type can be substantially the same as the average dopant dose of the IGBT emitter region 103, and the average dopant dose of each of the plurality of first sub-regions 1091 of the first conductivity type can be substantially the same as the average dopant dose of the diode cathode region 104. The design of the distribution and size of the doped region 109 with respect to the first sub-regions 1091 and the second sub-regions 1092 can be selected depending on the forward current density, the reverse recovery current density, the semiconductor body thickness d, and the dopant concentration of the field stop layer 108. For example, the higher the current density, the smaller the size. The size can be, for example, less than 30% of the semiconductor body thickness d, or less than 10% of the semiconductor body thickness d, or even less than 5% of the semiconductor body thickness d.

[0141] For example, in the doped region 109, it is, for example, by means of, as in Figure 14 (B1) and Figure 14 In the case of the mixed region formed by the pn strip structure shown in (B2), the diode performance is only slightly affected, but the reverse recovery behavior of RC IGBT 1 is improved.

[0142] Now refer to Figure 21 This will explain yet another further embodiment of the RC IGBT 1. In addition to the further blocking region 105 in diode segments 1-22, this embodiment can present the above-described... Figures 1 to 20 All characteristics explained. According to Figure 21 In contrast, in this embodiment, the body region 102 of diode segments 1-22 extends further along the vertical direction Z than the body region 102 in IGBT segments 1-21, and is at least 150% further along the vertical direction Z than the deepest level of the body region 102 in IGBT segments 1-21. For example, the blocking region 107 of transition segments 1-23 and the body region 102 of diode segments 1-22 have a common vertical extension of at least 20% of the total vertical extension of the blocking region 107. As illustrated, the "deep" body region 102 of diode segments 1-22 can even extend beyond the bottom of the trench. The "deep" body region 102 of diode segments 1-22 may be unstructured laterally and extends uniformly within the total lateral extension TLE2 of diode segments 22.

[0143] In an embodiment, the "deep" body region 102 can improve the controllability and / or performance of the RC IGBT 1 due to the beneficial distribution of potential near the front side 110 in the diode segments 1-22.

[0144] A method for forming an RC IGBT is also provided herein. The method includes forming the following components: an active region having an IGBT segment, a diode segment, and a transition segment between the IGBT segment and the diode segment, wherein the IGBT segment and the diode segment are adjacent to the transition segment from opposite lateral directions; an edge termination region surrounding the active region; a semiconductor body having a front side and a back side, the thickness of the semiconductor body being defined as a distance along a vertical direction between the front side and the back side, wherein the total lateral extension of the transition segment reaches at least 30% of the thickness of the semiconductor body; a plurality of trenches arranged in each of the IGBT segment, the diode segment, and the transition segment, each trench extending vertically from the front side into the semiconductor body and including a trench electrode isolated from the semiconductor body by a trench insulator, wherein two adjacent trenches define a corresponding mesa portion in the semiconductor body; a first load terminal at the front side of the semiconductor body and a second load terminal at the back side of the semiconductor body. The IGBT segment is configured to conduct a forward load current between the first load terminal and the second load terminal. The diode segment is configured to conduct reverse load current between a first load terminal and a second load terminal. The method further includes forming a control terminal for controlling a forward load current, wherein the average density of trench electrodes electrically connected to the control terminal in the IGBT segment is at least twice the average density of trench electrodes connected to the control terminal in the transition segment. The method further includes forming: a drift region of a first conductivity type, which is in the semiconductor body and extends into each of the IGBT segment, the diode segment, and the transition segment; and a body region of a second conductivity type, which is formed in a mesa portion of the semiconductor body and extends into each of the IGBT segment, the diode segment, and the transition segment. At least a portion of the body region is electrically connected to the first load terminal, wherein at least in the transition segment, the body region forms a pn junction with respect to a sub-segment of the mesa portion of the first conductivity type. The method further includes forming a first conductivity barrier region at least in the transition segment, having a peak dopant concentration at least 100 times larger than the average dopant concentration of the drift region and being disposed at least in a portion of the mesa sub-segment. The average dopant dose in the mesa portion of the transition section is at least 1.2 times higher than the average dopant dose in the mesa portion of the diode section.

[0145] An exemplary embodiment of the method corresponds to the embodiment of the RC IGBT 1 described above. In one embodiment, the method includes using a mask that is laterally structured for forming a blocking layer, the blocking layer including at least a blocking region 107 and optionally including at least one of a further blocking region 105 and yet another further blocking region 106, as explained above.

[0146] The embodiments related to RC IGBT and the corresponding processing methods have been explained above.

[0147] For example, these RC IGBTs are based on silicon (Si). Therefore, the single-crystal semiconductor region or layer (e.g., semiconductor body 10 and its regions / bands, such as regions, etc.) can be single-crystal Si regions or Si layers. In other embodiments, polycrystalline silicon or amorphous silicon can be used.

[0148] However, it should be understood that the semiconductor body 10 and its regions / bands can be made of any semiconductor material suitable for manufacturing semiconductor devices. Examples of such materials include, but are not limited to: basic semiconductor materials such as silicon (Si) or germanium (Ge); group IV compound semiconductor materials such as silicon carbide (SiC) or silicon germanium (SiGe); binary, ternary, or quaternary III-V semiconductor materials such as gallium nitride (GaN), gallium arsenide (GaAs), gallium phosphide (GaP), indium phosphide (InP), indium gallium phosphide (InGaPa), aluminum gallium nitride (AlGaN), aluminum indium nitride (AlInN), indium gallium nitride (InGaN), aluminum gallium indium nitride (AlGaInN), or indium gallium arsenide phosphide (InGaAsP); and binary or ternary II-VI semiconductor materials such as cadmium telluride (CdTe) and mercury cadmium telluride (HgCdTe). The aforementioned semiconductor materials are also referred to as "homogeneous junction semiconductor materials." When two different semiconductor materials are combined, a heterojunction semiconductor material is formed. Examples of heterojunction semiconductor materials include, but are not limited to, aluminum gallium nitride (AlGaN)-aluminum gallium indium nitride (AlGaInN), indium gallium nitride (InGaN)-aluminum gallium indium nitride (AlGaInN), indium gallium nitride (InGaN)-gallium nitride (GaN), aluminum gallium nitride (AlGaN)-gallium nitride (GaN), indium gallium nitride (InGaN)-aluminum gallium nitride (AlGaN), and silicon-silicon carbide (Si). x C 1-x (and silicon-SiGe heterojunction semiconductor materials. For power semiconductor switching applications, Si, SiC, GaAs, and GaN materials are currently the main materials used.)

[0149] For ease of description, spatial relative terms such as "below," "below," "down," "above," and "up" are used to explain the positioning of one element relative to a second element. These terms are intended to cover the different orientations of the corresponding devices, other than those depicted in the figures. Furthermore, terms such as "first," "second," etc., are also used to describe various elements, areas, segments, etc., without any intention of limitation. Throughout the description, the same terms refer to the same elements.

[0150] As used herein, the terms “having,” “containing,” “including,” “comprising,” “including,” and “presenting” are open-ended terms that indicate the presence of the declared element or feature but do not exclude additional elements or features.

[0151] While taking into account the above variations and scope of application, it should be understood that the invention is not limited to the foregoing description or the accompanying drawings. Rather, the invention is limited only by the following claims and their legal equivalents.

Claims

1. An RC IGBT (1), comprising: An active region (1-2) has an IGBT segment (1-21), a diode segment (1-22), and a transition segment (1-23) between the IGBT segment (1-21) and the diode segment (1-22), wherein the IGBT segment (1-21) and the diode segment (1-22) are adjacent to the transition segment (1-23) from opposite lateral directions; Termination region (1-3) surrounding the active region (1-2); A semiconductor body (10) having a front side (110) and a back side (120), the thickness (d) of the semiconductor body (10) being defined as the distance along the vertical direction (Z) between the front side (110) and the back side (120), wherein the total lateral extension (TLE) of the transition segments (1-23) reaches at least 30% of the thickness (d) of the semiconductor body; Multiple trenches (14, 15, 16) are arranged in each of the IGBT sections (1-21), diode sections (1-22), and transition sections (1-23), each trench (14, 15, 16) extending from the front side (110) into the semiconductor body (10) in a vertical direction (Z) and including trench electrodes (141, 151, 161) isolated from the semiconductor body by trench insulators (142, 152, 162), wherein two adjacent trenches define a corresponding mesa portion (17) in the semiconductor body (10); A first load terminal (11) at the front side (110) of the semiconductor body and a second load terminal (12) at the back side (120) of the semiconductor body, wherein, The IGBT section (1-21) is configured to conduct positive load current between the first load terminal (11) and the second load terminal (12); and The diode section (1-22) is configured to conduct reverse load current between the first load terminal (11) and the second load terminal (12); A control terminal (13) is used to control the forward load current, wherein the average density of the trench electrodes (141) electrically connected to the control terminal (13) in the IGBT section (1-21) is at least twice the average density of the trench electrodes (141) connected to the control terminal (13) in the transition section (1-23). A drift region (100) of the first conductivity type is formed in the semiconductor body (10) and extends into each of the IGBT segments (1-21), diode segments (1-22) and transition segments (1-23); A second conductivity type body region (102) is formed in the mesa portion of the semiconductor body (10) and extends into each of the IGBT segments (1-21), diode segments (1-22), and transition segments (1-23), wherein at least a portion of the body region (102) is electrically connected to the first load terminal (11), and wherein at least in the transition segments (1-23), the body region (102) forms a pn junction with respect to a sub-segment of the mesa portion (17) of the first conductivity type, wherein: At least in the transition sections (1-23), a first conductivity type blocking region (107) having a peak dopant concentration at least 100 times larger than the average dopant concentration of the drift region (100) is arranged at least in the portion of the mesa sub-section that is adjacent to the body region (102). The average dopant dose of the mesa portion in the transition section (1-23) is at least 1.2 times higher than the average dopant dose of the mesa portion in the diode section (1-22).

2. The RC IGBT (1) according to claim 1, wherein, Regarding the volume of the active region (1-2), the ratio between the IGBT section (1-21) and the diode section (1-22) is at least 2:

1.

3. The RC IGBT (1) according to claim 1 or 2, wherein at least a portion of the body region (102) in the IGBT segment (1-21) is coupled to the drift region (100) without the blocking region (107), and / or wherein at least a portion of the body region (102) in the diode segment (1-22) is coupled to the drift region (100) without the blocking region (107).

4. The RC IGBT (1) according to claim 1 or 2, wherein, The average dopant dose in the mesa portion of the IGBT segment (1-21) is at most five-sixths of the average dopant dose in the mesa portion of the transition segment (1-23).

5. The RC IGBT (1) according to claim 1 or 2, wherein, At least one of the average dopant dose of the mesa sub-parts in the IGBT segment (1-21), the average dopant dose of the mesa sub-parts in the diode segment (1-22), and the average dopant dose of the mesa sub-parts in the transition segment (1-23) is achieved by means of the lateral structure of the barrier layer including the barrier region (107).

6. The RC IGBT (1) according to claim 1 or 2, wherein, The average dopant dose of the blocking region (107) is at least 20% and no more than 500% of the average dopant dose of the body region (102) in the transition region (1-23).

7. The RC IGBT (1) according to claim 1 or 2, further comprising an IGBT emitter region (103) of a second conductivity type that is electrically connected to the second load terminal (12) and coupled to the drift region (100) in the IGBT segment (1-21).

8. The RC IGBT (1) according to claim 1 or 2, further comprising a diode cathode region (104) of a first conductivity type electrically connected to the second load terminal (12) and coupled to the drift region (100) in the diode section (1-22).

9. The RC IGBT (1) according to claim 1 or 2, wherein, Each of the trenches (15, 16) extending into the transition section (1-23) is either electrically floated or electrically connected to a potential different from that of the control terminal (13).

10. The RC IGBT (1) according to claim 1 or 2, wherein, Each of at least 80% of the trenches (14, 15, 16) extending into the transition sections (1-23) is either electrically floated or electrically connected to a potential different from that of the control terminal (13), and wherein at least one of the remaining at most 20% of the trenches (14) extending into the transition sections (1-23) is electrically connected to the control terminal (13) for forming at least one local IGBT cell in the transition sections (1-23).

11. The RC IGBT (1) according to claim 10, wherein, The blocking region (107) in the transition section (1-23) is laterally structured such that no lateral overlap is formed between the blocking region (107) and the at least one local IGBT unit in the transition section (1-23).

12. The RC IGBT (1) according to claim 1 or 2, wherein, In each of the IGBT sections (1-21), diode sections (1-22), and transition sections (1-23), the trenches (14, 15, 16) are arranged laterally adjacent to each other according to the same lateral trench spacing.

13. The RC IGBT (1) according to claim 12, wherein, Lateral trench spacing defines a lateral distance between two adjacent trenches that is no more than 1 / 30 of the semiconductor body thickness (d).

14. The RC IGBT (1) according to claim 1 or 2, further comprising a further blocking region (105) of a first conductivity type in the diode segment (1-22), the further blocking region (105) having an average dopant concentration at least 100 times that of the average dopant concentration of the drift region (100) and extending laterally at least 10% of the total lateral extension of the diode segment (1-22), wherein at least a portion of the body region (102) in the diode segment (1-22) is coupled to the drift region (100) at least by means of the further blocking region (105).

15. The RC IGBT (1) according to claim 14, wherein, The barrier zone (107) of the transition section (1-23) and the further barrier zone (105) form a continuous barrier layer.

16. The RC IGBT (1) according to claim 1 or 2, further comprising a further blocking region (106) of a first conductivity type in the IGBT segment (1-21), the further blocking region (106) having a peak dopant concentration at least 100 times greater than the average dopant concentration of the drift region (100) and extending laterally at least 10% of the total lateral extension of the IGBT segment (1-21), wherein at least a portion of the body region (102) in the IGBT segment (1-23) is coupled to the drift region (100) at least by means of the further blocking region (106).

17. The RC IGBT (1) according to claim 16, wherein, The barrier zone (107) of the transition section (1-23) and another further barrier zone (106) form a continuous barrier layer.

18. The RC IGBT (1) according to claim 1 or 2, further comprising a doped region (109) in the transition section (1-21), the doped region (109) being electrically connected to the second load terminal (12) and coupled to the drift region (100) and having the same total lateral extension as the transition section (1-21).

19. The RC IGBT (1) according to claim 18, wherein: The doped region (109) has a second conductivity type; or The doped region (109) is a mixed region having a plurality of sub-regions (1091) of a first conductivity type electrically connected to the second load terminal (12) and coupled to the drift region (100) and a plurality of second sub-regions (1092) of a second conductivity type electrically connected to the second load terminal (12) and coupled to the drift region (100); or The doped region (109) has a second conductivity type, and the RC IGBT further includes a diode cathode region (104) of a first conductivity type in the diode segment (1-22) that is electrically connected to the second load terminal (12) and coupled to the drift region (100), and one or more sub-regions (1041) of the second conductivity type that are electrically connected to the second load terminal (12) and coupled to the drift region (100) are interrupted laterally.

20. The RC IGBT (1) according to claim 18, wherein, The doped region (109) has a second conductivity type, and the IGBT segment (1-21) includes an IGBT emitter region (103) of the second conductivity type that is electrically connected to the second load terminal (12) and coupled to the drift region (100), wherein: The IGBT emitter region (103) is a laterally structured region having a plurality of highly doped IGBT emitter regions (1031) of a second conductivity type electrically connected to the second load terminal (12) and coupled to the drift region (100), and a plurality of less doped IGBT emitter regions (1032) of a second conductivity type electrically connected to the second load terminal (12) and coupled to the drift region (100); and / or The doped region (109) is a region that is structured laterally, having a plurality of highly doped subregions (1091) of a second conductivity type that are electrically connected to the second load terminal (12) and coupled to the drift region (100), and having a plurality of less doped subregions (1092) of a second conductivity type that are electrically connected to the second load terminal (12) and coupled to the drift region (100).

21. The RC IGBT (1) according to claim 1 or 2, wherein, The body region (102) of the diode segment (1-22) extends further along the vertical direction (Z) than the body region (102) in the IGBT segment (1-21), and is at least 150% further along the vertical direction (Z) than the deepest level of the body region (102) in the IGBT segment (1-21).

22. A method of forming an RC IGBT (1), comprising forming the following components: An active region (1-2) has an IGBT segment (1-21), a diode segment (1-22), and a transition segment (1-23) between the IGBT segment (1-21) and the diode segment (1-22), wherein the IGBT segment (1-21) and the diode segment (1-22) are adjacent to the transition segment (1-23) from opposite lateral directions; Termination region (1-3) surrounding the active region (1-2); A semiconductor body (10) having a front side (110) and a back side (120), the thickness of the semiconductor body (10) being defined as the distance along the vertical direction (Z) between the front side (110) and the back side (120), wherein the total lateral extension of the transition sections (1-23) reaches at least 30% of the thickness (d) of the semiconductor body; Multiple trenches (14, 15, 16) are arranged in each of the IGBT sections (1-21), diode sections (1-22), and transition sections (1-23), each trench (14, 15, 16) extending from the front side (110) into the semiconductor body (10) in a vertical direction (Z) and including trench electrodes (141, 151, 161) isolated from the semiconductor body by trench insulators (142, 152, 162), wherein two adjacent trenches define a corresponding mesa portion (17) in the semiconductor body (10); A first load terminal (11) at the front side (110) of the semiconductor body and a second load terminal (12) at the back side (120) of the semiconductor body, wherein, The IGBT segment (1-21) is configured to conduct positive load current between the first load terminal (11) and the second load terminal (12); and The diode section (1-22) is configured to conduct reverse load current between the first load terminal (11) and the second load terminal (12); A control terminal (13) is used to control the forward load current, wherein the average density of the trench electrodes (141) electrically connected to the control terminal (13) in the IGBT section (1-21) is at least twice the average density of the trench electrodes (141) connected to the control terminal (13) in the transition section (1-23). A drift region (100) of the first conductivity type is formed in the semiconductor body (10) and extends into each of the IGBT segments (1-21), diode segments (1-22) and transition segments (1-23); A second conductivity type body region (102) is formed in the mesa portion of the semiconductor body (10) and extends into each of the IGBT segments (1-21), diode segments (1-22) and transition segments (1-23), wherein at least a portion of the body region (102) is electrically connected to the first load terminal (11), and wherein at least in the transition segments (1-23), the body region (102) forms a pn junction with respect to a sub-segment of the mesa portion (17) of the first conductivity type; The method further includes: A first conductivity type blocking region (107) is formed at least in the transition section (1-23), having a peak dopant concentration that is at least 100 times larger than the average dopant concentration of the drift region (100), and is arranged at least in the portion of the mesa sub-section that is in contact with the body region (102), wherein the average dopant dose of the mesa sub-section in the transition section (1-23) is at least 1.2 times higher than the average dopant dose of the mesa sub-section in the diode section (1-22).

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