Diodes with structured blocking regions

Abstract

A diode with a structured blocking region is disclosed. A power semiconductor device includes: an active region having a diode segment; an edge-terminating region surrounding the active region; a semiconductor body; a first load terminal at a front side of the semiconductor body and a second load terminal at a back side of the semiconductor body; a drift region of a first conductivity type formed in the semiconductor body and extending into the diode segment; a plurality of trenches arranged in the diode segment; a body region of a second conductivity type; and a blocking region of a first conductivity type, wherein the blocking region has a dopant concentration at least 100 times greater than the average dopant concentration of the drift region and has a dopant dose greater than that of the body region. The blocking region has a lateral structure, wherein at least 50% of the body region in the diode segment is coupled to the drift region at least by means of the blocking region; and at least 5% of the body region in the diode segment is coupled to the drift region without the blocking region.

Description

Technical Field

[0001] This specification relates to embodiments of power semiconductor devices and embodiments of methods for processing power semiconductor devices. In particular, this specification relates to embodiments of diode segments (e.g., in RC IGBTs or in diodes) and corresponding processing methods, wherein the diode segments have laterally structured, highly doped barrier regions between the body region and the drift region. 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] Of course, it is possible to provide reverse current capability by means of a separate diode; the separate diode is, for example, a diode connected in anti-parallel to a conventional (non-reverse conduction) IGBT.

[0008] Whether a diode is provided as a discrete diode or as a diode segment in a reverse-conducting transistor, the typical design goal for a diode is to achieve a specific anode injection efficiency. Summary of the Invention

[0009] According to an embodiment, a power semiconductor device includes: an active region having a diode segment; an edge-terminating region surrounding the active region; a semiconductor body having a front side and a back side; 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, wherein the diode segment is configured to conduct a diode load current between the first load terminal and the second load terminal; a drift region of a first conductivity type formed in the semiconductor body and extending into the diode segment; a plurality of trenches arranged in the diode 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 body region of a second conductivity type formed in the mesa portion of the semiconductor body and electrically connected to the first load terminal; and a first conductivity blocking region between the body region and the drift region in the diode segment, wherein the blocking region has a dopant concentration at least 100 times greater than the average dopant concentration of the drift region and has a dopant dose greater than that of the body region. The blocking region has a lateral structure, according to which at least 50% of the body region in the diode segment is coupled to the drift region at least by means of the blocking region; and at least 5% of the body region in the diode segment is coupled to the drift region in the absence of the blocking region.

[0010] According to another embodiment, a method of processing a power semiconductor device includes forming: an active region having a diode segment; an edge termination region surrounding the active region; a semiconductor body having a front side and a back side; 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, wherein the diode segment is configured to conduct diode load current between the first load terminal and the second load terminal; a drift region of a first conductivity type formed in the semiconductor body and extending into the diode segment; a plurality of trenches arranged in the diode 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 body region of a second conductivity type formed in the mesa portion of the semiconductor body and electrically connected to the first load terminal; and a first conductivity blocking region between the body region and the drift region in the diode segment, wherein the blocking region has a dopant concentration at least 100 times greater than the average dopant concentration of the drift region and has a dopant dose greater than that of the body region. The blocking region has a lateral structure, according to which at least 50% of the body region in the diode segment is coupled to the drift region at least by means of the blocking region; and at least 5% of the body region in the diode segment is coupled to the drift region in the absence of the blocking region.

[0011] For example, the diode segment mentioned herein is not integrated into the IGBT segment; for example, the mesa portion of the diode segment does not include one or more source regions of the first conductivity type that are electrically connected to the first load terminal.

[0012] 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

[0013] 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:

[0014] Figure 1 A segment of a horizontally projected power semiconductor device according to one or more embodiments is illustrated schematically and exemplary.

[0015] Figure 2 The simplified design of a power semiconductor device according to one or more embodiments is illustrated schematically and exemplary.

[0016] Figure 3 A section of the vertical cross-section of a diode segment of a power semiconductor device according to some embodiments is illustrated schematically and exemplaryly.

[0017] Figure 4 A section of the vertical cross-section of an IGBT segment of a power semiconductor device according to some embodiments is illustrated schematically and exemplary.

[0018] Figure 5 The illustration schematically and exemplaryly depicts some variations of one or more diode segments and one or more IGBT segments of a power semiconductor device according to one or more embodiments in their respective horizontal projections.

[0019] Figure 6 The illustration schematically and exemplaryly depicts vertical cross-sections of different trench types that may be portions of a power semiconductor device according to one or more embodiments;

[0020] Figure 7 A segment of a vertical cross-section of a power semiconductor device according to some embodiments is illustrated schematically and exemplary.

[0021] Figures 8 to 9 Both of these schematically and exemplary illustrate corresponding segments of a horizontal projection of a power semiconductor device according to some embodiments;

[0022] Figure 10 A segment of a perspective projection of a power semiconductor device according to some embodiments is illustrated schematically and exemplary.

[0023] Figure 11 The illustration schematically and exemplaryly depicts some variations of a power semiconductor device according to one or more embodiments in corresponding segments of a vertical cross-section; and

[0024] Figures 12 to 15 Each schematic and exemplary illustration depicts a corresponding segment of a horizontal projection of a power semiconductor device according to some embodiments. Detailed Implementation

[0025] 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.

[0026] 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.

[0027] 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.

[0028] 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.

[0029] 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".

[0030] 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.

[0031] 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.

[0032] 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.

[0033] The specific embodiments described in this specification relate to, but are not limited to, power semiconductor devices, such as diodes or RC IGBTs arranged in a strip-like unit configuration, for example, power semiconductor devices that can be used in power converters or power supplies. Therefore, in embodiments, such power semiconductor devices 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, a power semiconductor device may include multiple power semiconductor units, such as monolithically integrated diode units, derivatives of monolithically integrated diode units, monolithically integrated IGBT units, and / or derivatives thereof. Such diode / transistor units can be integrated in a power semiconductor module. Multiple such units can constitute a cell field region arranged within the active region of the power semiconductor device.

[0034] As used herein, the term "power semiconductor device" is intended to describe a single-chip power semiconductor device having high voltage blocking capability and / or high current carrying capability. In other words, embodiments of the power semiconductor devices described herein are single-chip power semiconductor devices (e.g., RC IGBTs or diodes) 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).

[0035] For example, the power semiconductor devices described below can be single-chip power semiconductor devices, which are arranged in a strip-like unit configuration and configured for use as power components in low, medium, and / or high voltage applications. Several single-chip power semiconductor devices can be integrated into a module to form a power semiconductor module, such as an RC IGBT module or diode module for installation and use in low, medium, and / or high voltage applications (such as major household appliances, general-purpose drives, electric drive systems, servo drives, traction, higher power transmission facilities, etc.).

[0036] For example, the term "power semiconductor device" 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.

[0037] Figure 1 A simplified schematic and exemplary horizontal projection of a power semiconductor device 1 according to one or more embodiments is illustrated. The power semiconductor device 1 may be, for example, a single-chip diode. In another embodiment, the power semiconductor device 1 is a single-chip RC IGBT.

[0038] To describe the configuration of power semiconductor device 1, the following will also refer to... Figures 2 to 5 .

[0039] The power semiconductor device 1 includes an active region 1-2 having a diode segment 1-22 and optionally an IGBT segment 1-21.

[0040] 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 terminated laterally by edge 1-4. Edge 1-4 can form the chip edge of power semiconductor device 1.

[0041] 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 power semiconductor devices such as diodes and RC IGBTs. Specifically, the active regions 1-2 are primarily configured for forward (and optionally reverse) load current conduction and optional switching purposes, while the edge-termination regions 1-3 primarily fulfill 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 regions 1-2.

[0042] This manual mainly covers the active regions 1-2.

[0043] As in Figure 5 As shown in the diagram, if implemented as an RC IGBT, the power semiconductor device 1 may include a plurality of substantially equivalent IGBT segments 1-21 and a plurality of substantially equivalent diode segments 1-22.

[0044] Different segments 1-21 and 1-22 can be laterally distributed within the active region 1-2. Figure 1 and Figure 5 The diagram illustrates several illustrative examples.

[0045] In the embodiment, the active region 1-2 consists of one or more diode segments 1-22 and zero or more IGBT segments 1-21.

[0046] However, it should be understood that, according to one or more embodiments described herein, diode sections 1-22 are not integrated into IGBT sections 1-21; for example, the mesa portion (reference numeral 17) in diode sections 1-22 does not include one or more source regions (reference numeral 101) of a first conductivity type that are electrically connected to a first load terminal (reference numeral 11).

[0047] For example, one or more diode segments 1-22 that are not integrated into IGBT segments 1-21 and are not electrically connected to the first load terminal 11 by the source region 101 of the first conductivity type constitute a significant portion, such as a major portion, of the active region 1-2. Therefore, according to an embodiment, each of the one or more diode segments 1-22 mentioned herein may be a portion of the active region 1-2 that is "only a large diode".

[0048] according to Figure 1 The variant shown in the diagram includes an active region 1-2 comprising a diode segment 1-22 or correspondingly consisting of a diode segment 1-22. According to... Figure 5 The active region 1-2 additionally has one or more IGBT segments 1-21. For example, according to variations (A), (B), (E), (F), (L), and (M), two or four (or more or fewer) similar strip-shaped diode segments 1-22 are embedded in an IGBT segment 1-21 adjacent to the edge termination region 1-3. The similar strip-shaped diode segments 1-22 can vary in size (e.g., width and / or length) and orientation. Combinations of similar strip-shaped diode segments 1-22 with different orientations are also possible, as exemplarily illustrated in variations (C) and (D), for example, enabling the implementation of continuous diode segments 1-22 having an H structure or a derivative thereof. In other embodiments, one or more similar circular diode segments 1-22 are embedded in an IGBT segment 1-21, as illustrated in variations (G), (H), (I), (N), and (O). In other embodiments, one or more, for example, strip-like IGBT segments 1-21 are embedded within consecutive diode segments 1-22, as illustrated in variations (J) and (K). In addition to the strip-like diode segments 1-22 embedded within a consecutive IGBT segment 1-21, the IGBT segment 1-21 may also be surrounded by additional frame-like diode segments 1-22 connected to edge termination regions 1-3, see variations (L), (M), (N), and (O).

[0049] 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 the total (one or more) IGBT segments 1-21 and the total (one or more) diode segments 1-22 is at least 1.5:1, 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 the power semiconductor device 1 is employed. In an embodiment, at least 75% of the total volume of the active region 1-2 may be used to form the (one or more) IGBT segments, and the remaining 25% (or a lower percentage share) of the active region 1-2 may be used to form the (one or more) diode segments 1-22. According to the embodiment, regardless of the selected lateral spatial distribution of IGBT segments 1-21 and diode segments 1-22, it can be ensured that the ratio between (one or more) IGBT segments 1-21 and (one or more) diode segments 1-22 with respect to the volume of the active region 1-2 is even greater than 3:1.

[0050] Referring below to "Diode Segments 1-22" and "IGBT Segments 1-21", it should be understood that the explanations provided below regarding these segments 1-21 and 1-22 can be applied to each segment 1-21 or corresponding 1-22 provided in the active region 1-2. For example, if zero or more 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).

[0051] Currently, the focus is still on Figure 2 The semiconductor body 10 of the power semiconductor device 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 1 and Figure 5Furthermore, 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.

[0052] In an embodiment, the total lateral extension of IGBT segments 1-21 (if present) reaches at least 50% of the semiconductor body thickness d. The total lateral extension of IGBT segments 1-21 may also be greater than 50% of the thickness d, for example, greater than 2×d or even greater than 2.5×d.

[0053] In an embodiment, the total lateral extension of diode segments 1-22 reaches at least 20% of the semiconductor body thickness d. The total lateral extension of diode segments 1-22 may also be greater than 30% of the thickness d, for example, greater than 0.5 × d or even greater than d. For example, the horizontal cross-sectional area of ​​diode segments 1-22 has a minimum lateral extension reaching at least the semiconductor body thickness d.

[0054] The first load terminal 11 is located at the front side 110 of the semiconductor body and the second load terminal 12 is located at the back side 120 of the semiconductor body.

[0055] If present, IGBT sections 1-21 are configured to conduct positive 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.

[0056] Diode segments 1-22 are configured to conduct diode 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. If both diode segments 1-22 and IGBT segments 1-21 are implemented in the active region 1-2 of the power semiconductor device 1, an RC-IGBT is formed, and the diode load current can therefore be considered as a reverse load current. However, it is emphasized again that the embodiments also cover variations in which the active region 1-2 is equipped with only one or more diode segments 1-22 without any IGBT segments 1-21. Therefore, in the latter case, the power semiconductor device 1 is a power semiconductor diode.

[0057] In an embodiment, the diode section 1-22 that conducts the diode load current may be spatially separated from the IGBT section 1-21 that conducts the forward load current. As indicated above, the diode section 1-22 is not part of the IGBT section 1-21 but is separate from it, and does not include any source region 101 of the first conductivity type electrically connected to the first load terminal 11; rather, according to some embodiments, the diode section 1-22 is a region of the active region 1-2 that is only a large diode.

[0058] Furthermore, in an embodiment, diode sections 1-22 are independent of control signals (e.g., control signals provided to control electrode 141 mentioned below). This means that diode sections 1-22 can be configured such that they conduct diode 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 section), regardless of the control signals provided to IGBT sections 1-21 (if they are present at all).

[0059] If implemented as an RC IGBT, the power semiconductor device 1 may further include a control terminal 13 for controlling the forward load current. The control terminal 13 may also be located at the front side 110.

[0060] 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.

[0061] According to terminology typically associated with a diode (where control terminal 13 may not be present), the first load terminal 11 may be an anode terminal, and the second load terminal 12 may be a cathode terminal.

[0062] 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.

[0063] 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 3 and Figure 4As 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.

[0064] 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.

[0065] 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(s) segments 1-22 and / or IGBT(s) segments 1-21 (if present). Therefore, the lateral boundary of the active region 1-2 can be defined at the front side 110. For example, if implemented as an RC IGBT, this lateral boundary can be defined by the outermost source(s) 101 (see the explanation below in more detail). For example, all functional elements capable of conducting diode load current and (optionally) forward (IGBT) load current appear in the vertical projection of the active region 1-2 of the power semiconductor device 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(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.

[0066] In an embodiment, the edge termination region 1-3 and the active region 1-2 may be arranged symmetrically to each other, for example, about the central vertical axis of the power semiconductor device 1.

[0067] 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.

[0068] Still referencing Figure 3 , Figure 4and Figure 6 Multiple trenches 14, 15, 16 are arranged in diode sections 1-22 and also in IGBT sections 1-21 (if present). 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 corresponding trench insulators 142, 152, 162, wherein two adjacent trenches define a corresponding mesa portion 17 in the semiconductor body 10.

[0069] Each trench 14, 15, 16 can have a strip-like configuration, for example, as shown in... Figures 8 to 10 and Figure 12 As best illustrated in one of the horizontal / perspective projections, this means that the corresponding groove length (e.g. along the second lateral direction Y) is much larger than the corresponding groove width (e.g. along the first lateral direction X).

[0070] As will be explained further below, different types of trenches may be provided in sections 1-21 and / or 1-22.

[0071] The 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 the control electrode 141.

[0072] The 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 the source electrode 161.

[0073] The 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, the trench 15 is a floating trench, and the trench electrode 151 is not connected to a defined potential but is electrically floating. In another embodiment, the trench 15 is a dummy trench, and the trench electrode 151 is electrically connected to the control terminal 13, but does not directly control the conduction of the forward load current because the unconnected source region 101 (connected to the first load terminal) is arranged adjacent to the trench 15. In yet 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.

[0074] Each groove type may have equal dimensions in width (along the first lateral direction X), depth (along the vertical direction Z, for example, the distance between the front side 110 and the bottom of the groove), and / or length (along the second lateral direction Y).

[0075] If present, IGBT segments 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.

[0076] Similarly, diode segments 1-22 may include multiple diode units, each 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.

[0077] As indicated above, in one embodiment, trenches 14, 15, and 16 are arranged in both diode sections 1-22 and IGBT sections 1-21. For example, trenches 14, 15, and 16 in both IGBT sections 1-21 and diode sections 1-22 are arranged laterally adjacent to each other 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 and 1-22.

[0078] Regardless of whether IGBT sections 1-21 are present or not, the lateral trench spacing can limit the lateral distance between two adjacent trenches to no more than 1 / 30 of the semiconductor body thickness d. For example, the lateral width of the mesa portion 17 in both diode sections 1-22 and IGBT sections 1-21 can be the same.

[0079] Additionally, each of trenches 14, 15, and 16 may have the same trench depth (total vertical extension). For example, the lateral trench spacing may be limited to a lateral distance of no more than 50% or 30% of the trench depth between two adjacent trenches.

[0080] In an embodiment, the lateral trench spacing can define a lateral distance of no more than 10 μm, 5 μm, 1 μm, or 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.

[0081] Therefore, the width of each countertop portion 17 is within the range defined by the spacing of the transverse grooves.

[0082] As explained above, the lateral trench spacing can be the same for both sections 1-21 and 1-22. This means that the average density of the trench electrodes can also be the same for both sections 1-21 and 1-22. However, the trench pattern—such as the arrangement of different types of trenches—can vary between sections 1-21 and 1-22. An exemplary 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 diode section 1-22 (which can even reach zero).

[0083] 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.

[0084] 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 diode sections 1-22 is 100, and no more than ten trench electrodes are control electrodes 141, resulting in a control electrode density of no more than 10%.

[0085] In an embodiment, at least 50% of the trench electrodes of the trenches in diode segments 1-22 are electrically connected to the first load terminal 11, that is, at least 50% of the trench electrodes of the trenches in diode segments 1-22 are the trench electrodes 161 of the source trench 16.

[0086] For example, the trenches in diode sections 1-22 are source trenches 16 or floating trenches 15; for example, all the trenches in diode sections 1-22 are source trenches 16. Furthermore, all or some of the mesa portions 17 in diode sections 1-22 can be electrically connected to the first load terminal 11, for example, by means of contact plugs 111.

[0087] In contrast, the trench type in (optional) IGBT sections 1-21 can vary; according to an embodiment, a successively repeating trench-mesa pattern corresponding to "kGkSoSoSoSoS" can be used to form the IGBT cell. Figure 7The 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 (i.e., 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, and "S" represents the source trench 16. Of course, different trench-mesa patterns can be used in other embodiments. For example, a dummy trench 15 (which is the same as the gate trench arranged between the non-contact mesa portions 17) can be included in the pattern of diode sections 1-22 and / or in the pattern of IGBT sections 1-21.

[0088] Still refer to Figure 3 , Figure 4 and Figure 6 And additionally refer to Figure 7 The power semiconductor device 1 further includes a drift region 100 of a first conductivity type, which is formed in the semiconductor body 10 and extends into the diode segments 1-22 and also extends into the IGBT segments 1-21 (if present).

[0089] A body region 102 of a second conductivity type is formed in the mesa portion 17 of the semiconductor body 10 and is formed in diode segments 1-22, and also in IGBT segments 1-21 (if present). At least a portion of the body region 102 is electrically connected to the first load terminal 11. The body region 102 may form pn junctions with respect to sub-segments 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 7 As illustrated in the figure, in this embodiment, not in each platform portion 17, the corresponding portion of the body region 102 is electrically connected to the first load terminal 11.

[0090] In IGBT sections 1-21, a source region 101 of a first conductivity type is disposed at the front side 110 and electrically connected to the first load terminal 11. The source region 101 is provided only partially in IGBT sections 1-21, for example, and does not extend into diode sections 1-22, for example.

[0091] 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 1021 therewith. The body region 102 isolates the source region 101 from the drift region 100.

[0092] 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 12.

[0093] The basic configuration of the IGBT cells in the (optional) IGBT sections 1-21 of the power semiconductor device 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.

[0094] 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.

[0095] 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 the IGBT segment 1-21 or the diode cathode region 104 of the diode segment 1-22.

[0096] 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.

[0097] 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.

[0098] Both the IGBT emitter region 103 of IGBT section 1-21 and the diode cathode region 104 of diode section 1-22 can be arranged to make electrical contact with the second load terminal 12.

[0099] In general, the IGBT emitter region 103 can act as an emitter of a second conductivity type. Furthermore, although the power semiconductor device 1 can be 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 -3Within the range; conversely, according to some embodiments, the diode cathode region 104 is exclusively formed in the diode segments 1-22.

[0100] Again, it is emphasized that the power semiconductor device 1 can be implemented as a power semiconductor diode without any IGBT units, i.e., without any source region 101, without any control trench 14 and without any IGBT emitter region 103.

[0101] In this embodiment, the average dopant concentration of the drift region 100 can be 10. 12 cm -3 Up to 10 14 cm -3 Within the range.

[0102] In this embodiment, the dopant concentration of each (optional) source region 101 can be 10. 19 cm -3 Up to 10 21 cm -3 Within the range.

[0103] 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.

[0104] In an embodiment, the dopant concentration of the (optional) field stop layer 108 can be 10. 14 cm -3 Up to 3×10 16 cm -3 Within the range.

[0105] In this embodiment, the dopant concentration of the (optional) IGBT emitter region 103 can be 10. 16 cm -3 Up to 10 18 cm -3 Within a certain range. However, in embodiments, the dopant concentration can vary along the lateral extension of the IGBT emitter region 103.

[0106] 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 (and even change the polarity) along the lateral extension of the diode cathode region 104.

[0107] It should be noted that Figure 3 and Figure 4The groove pattern shown in the figure is merely exemplary; other groove patterns will be described with reference to other figures.

[0108] In this embodiment, diode segments 1-22 are not equipped with a source region 101; for example, in diode segments 1-22, there is no doped semiconductor region of the first conductivity type electrically connected to the first load terminal. Instead, in order to form a diode configuration in diode segments 1-22 for conducting diode 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 blocking region 107 further described below), and along the vertical direction Z toward the second load terminal 12, there is a semiconductor path of only the first conductivity type, which is not interrupted by any further regions of the second conductivity type.

[0109] As explained above, in contrast to diode segments 1-22, according to an embodiment, optional IGBT segments 1-21 include at least one IGBT cell, wherein a segment of source region 101 is connected to a first load terminal 11 and is arranged adjacent to one of the control trenches 14 and isolated from drift region 100 (or, if present, another further blocking region 106) 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). Thus, the lateral boundary of IGBT segments 1-21 can be defined at 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 forward load current appear in the vertical projection of the IGBT segments 1-21 of the power semiconductor device 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 entire lateral extension of the IGBT segments 1-21.

[0110] In an embodiment, the contact plug 111 is part of a contact plug structure 111 of the power semiconductor device 1. Each contact plug 111 can be configured to make contact with a corresponding mesa portion 17 to electrically connect the corresponding mesa portion 17 to a first load terminal 11. As illustrated, each contact plug 111 can extend along the vertical direction Z from the front side 110 into the corresponding mesa portion 17. Further exemplary aspects of the contact plug structure will be described below.

[0111] Now refer to more details Figure 7The power semiconductor device 1 includes a first conductive barrier region 107 between the body region 102 and the drift region 100 in diode sections 1-22 (and regardless of whether optional IGBT sections 1-21 are present or not).

[0112] The blocking region 107 has a dopant concentration at least 100 times greater than the average dopant concentration of the drift region 100. For example, the blocking region 107 has a peak dopant concentration at least 100 times greater than the average dopant concentration of the drift region 100. For example, the average dopant concentration of the drift region 100 is determined in the section of the drift region 100 below the bottom of the trench.

[0113] Furthermore, the blocking region 107 has a larger dopant dose than the dopant dose of the body region 102; for example, the dopant dose of the blocking region is greater than 1.5 × the dopant dose of the body region.

[0114] It should be noted here that the dopant concentrations mentioned in the preceding paragraphs are all related to the dopant concentration of the first conductivity type; for example, the blocking region 107 is an n-blocking region 107, and the drift region 100 is an n-drift region 100. In contrast, the dopant dose of the body region 102 is related to the dopant concentration of the second conductivity type, while the dopant dose of the blocking region 107 is related to the dopant concentration of the first conductivity type.

[0115] For example, mentioned here In dopant dosage Each 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).

[0116] Furthermore, as mentioned here In dopant dosageEach can be defined as an average dopant dose taken along at least 1 μm of distance or width of mesa portion 17 in at least one of the lateral directions X / Y perpendicular to the vertical direction Z. The corresponding dopant dose can even be defined by an 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 comparison purposes, the dopant dose of barrier region 107 is determined along the same lateral and vertical distances as the dopant dose of body region 102 in diode segments 1-22. Furthermore, when determining the dopant dose of barrier region 107, the recesses 1071, mentioned further below, are not considered; that is, the integration path does not pass through recesses 1071 but only through those mesa portions in which barrier region 107 is implemented. For example, the dopant dose of the body region 102 is determined in a portion of the body region 102 by integrating the dopant concentration along a vertical path between the front side 110 and the pn junction 1021, without considering optional highly doped subregions (e.g., those with a dopant concentration greater than 1 × 10⁻⁶). 18 cm -3 The concentration of the doped material is typically arranged close to the front side to establish electrical contact for contact plug 111; that is, the integration path does not include such an optional highly doped contact portion of the body region 102.

[0117] Furthermore, the term "dopane dose" refers to an electrically active dopant of the same conductivity type. Therefore, changes in dopane dose can also be achieved by maintaining a constant dose of one dopant type in both portions and by applying anti-doping and / or damage doping. Additionally, differences in (net) dopant dose can be achieved through such means.

[0118] Furthermore, it should be understood that the integral path used to determine the dopant dosage does not extend beyond the boundary of the relevant semiconductor portion.

[0119] For example, the peak dopant concentration of the blocking region 107 can reach at least 1 × 10⁻⁶. 15 cm -3 , reaching at least 2×10 16 cm -3 Or even more than 5×10 17 cm -3 .

[0120] 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 the range.

[0121] For example, the dopant dose of the barrier region 107 can reach at least 1 × 10⁻⁶. 12 cm -2 , reaching at least 5×10 12 cm -2 Or even more than 2×10 13 cm -2 .

[0122] For example, the dopant dose in the body region 102 can be 1×10 12 cm -2 Up to 5×10 13 cm -2 Within the range, or within 5×10 12 cm -2 Up to 3×10 13 cm -2 Within the range. It should be noted here that the body region 102 can be configured equivalently in both diode segments 1-22 and (optionally) IGBT segments 1-21. For example, the body region 102 is not laterally structured with respect to diode segments 1-22 and IGBT segments 1-21. Therefore, the dopant dosage of the body region 102 indicated above can be equivalently present in both diode segments 1-22 and IGBT segments 1-21.

[0123] In the region where the blocking region 107 is implemented (again, not considering the recess 1071), the dopant dose of the blocking region 107 can be laterally uniform. This means that the blocking region 107 can be provided locally without a VLD configuration. However, as will be explained further below, due to the lateral structure of the blocking region 107, for example by means of the recess 1071, it can be ensured that, when viewed over the entire horizontal cross-section of diode segments 1-22, the effective n-dopant dose is directed towards the outer peripheral portion of diode segments 1-22 (see [link to documentation]). Figure 15 (Referencing reference number 1-222) decreases.

[0124] In addition to the relatively high dopant dose and dopant concentration as exemplarily described above, the barrier region 107 also has a lateral structure.

[0125] According to the lateral structure of the blocking region 107, at least 50% or at least 70% of the body region 102 in the diode segments 1-22 is coupled to the drift region 100 at least by means of the blocking region 107. For example, at least 80% of the body region 102 in the diode segments 1-22 is coupled to the drift region 100 at least by means of the blocking region 107.

[0126] Furthermore, based on the lateral structure of the blocking region 107, at least 5% of the body region 102 in the diode segments 1-22 is coupled to the drift region 100 in the absence of the blocking region 107.

[0127] Here, it should be noted that the body region 102 may extend throughout the entire lateral extension of the diode segments 1-22, for example, without being laterally structured, which is, of course, interrupted by trenches 14, 15, and 16. The percentage values ​​indicated above may refer to the lower "interface region" of the body region 102 that is connected to the drift region 100 or the blocking region 107.

[0128] In this embodiment, the coupling between the body region 102 and the drift region 100 (with or without the blocking region 107) is established within the platform portion 17. Therefore, in each platform portion 17, the coupling to the body region 102 may be formed by either the drift region 100 extending into the respective platform portion 17 or by the blocking region 107 extending into the respective platform portion 17.

[0129] For example, refer to Figure 7 As an example, in diode segments 1-22, the blocking region 107 extends only in selected areas of the mesa portion 17. For instance, in some mesa portions 17 of diode segments 1-22, the blocking region 107 is not provided or is provided only partially (with respect to the total lateral extension of the respective mesa portion 17 along the second lateral direction Y). If provided within the mesa portion 17, the blocking region 107 extends along the entire width of that mesa portion 17 (along the first lateral direction X).

[0130] According to the lateral structure of the blocking region 107, in an embodiment, the blocking region 107 laterally overlaps with at least 70% (e.g., at least 70% to 95%) of the horizontal cross-sectional area of ​​the diode segments 1-22. For example, the body region 102 in the diode segments 1-22 is coupled to the drift region 100 at least by means of the blocking region 107 in which the lateral overlap is established. In the remaining 5% to 30% of the horizontal cross-sectional area of ​​the diode segments 1-22 where no overlap is established, the recess 1071, which is filled with the portion of the drift region 100, forms a pn junction with the body region 102.

[0131] Therefore, in the embodiment, the recess 1071 of the blocking region 107 (which means that no relatively highly doped sub-region of the blocking region 107 is provided therein) overlaps laterally with the at least 5% of the body region 102 in the diode segments 1-22 that is coupled to the drift region 100 without the blocking region 107.

[0132] As explained above, the lateral distance between two adjacent trenches is defined by the (lateral) trench spacing of the pattern of trench 16 in diode segments 1-22.

[0133] Based on the lateral structure of the blocking region 107, in an embodiment, the lateral distance between two adjacent recesses 1071 of the blocking region 107 is defined by the blocking spacing of the pattern of the blocking region 107. The pattern can define the lateral structure of the blocking region 107. For example, the minimum value of the blocking spacing is greater than the minimum value of the groove spacing. For example, referring to… Figure 7 As an example, the minimum trench spacing is approximately twice the minimum blocking spacing. In short, the blocking area 107 can exhibit a coarser lateral structure compared to the structure of the trench pattern.

[0134] Meanwhile, the minimum value of the blocking spacing can be less than 50% of the thickness d of the semiconductor body 10, or even less than 25% of the thickness d, or even less than 10% of the thickness d (i.e., less than 0.1 × d). For example, regarding Figure 7 The blocking spacing can be approximately equal to the sum of the width of a groove 16 and the width of a platform portion 17.

[0135] Furthermore, for example, with regard to the blocking region 107 having a lateral structure through injection processing, it is possible that the lateral extension direction of the blocking region 107 is arranged orthogonally to the lateral extension of the groove pattern. In another embodiment, the lateral extension direction of the blocking region 107 is arranged parallel to the lateral extension of the groove pattern. For example, in Figure 7 The diagram illustrates the latter situation. Figure 10 An orthogonal arrangement is illustrated exemplarily in the diagram; the lateral structure of the blocking region 107 is achieved therein by one or more recesses 1071 provided in the second lateral direction Y along the lateral extension of the platform portion 17. Of course, a lateral structure of the blocking region 107 that combines parallel and orthogonal arrangements is also possible.

[0136] As indicated above, and also as in Figure 7As illustrated in the diagram, the power semiconductor device 1 may include one or more IGBT segments 1-21 in addition to the diode segments 1-22 within the active regions 1-2. For example, in this case, the power semiconductor device is an RC IGBT. Depending on the lateral structure of the blocking region 107, in an embodiment, at least 90% of the body region 102 in the IGBT segments 1-21 is coupled to the drift region 100 without the blocking region 107. Therefore, in this example, the blocking region 107 does not substantially extend into the IGBT segments 1-21. For example, the blocking region 107 does not extend into the IGBT segments 1-21 at all. In another embodiment, small sub-portions of the body region 102 in the IGBT segments 1-21 are also coupled to the drift region 100 by means of the blocking region 107.

[0137] The total vertical extension of the blocking area 107 can be in the range of 30% to 80% of the trench depth. For example, the blocking area 107 does not extend beyond the horizontal of the bottom of the trench in the vertical direction Z, but is exclusively formed in the platform portion 17.

[0138] In an embodiment, the barrier region 107 is a laterally structured barrier layer formed over the entire horizontal cross-section of diode segments 1-22. The barrier layer is interrupted by trenches and one or more recesses 1071 in the diode segments 1-22, which ensure that at least 50% of the body region 102 in the diode segments 1-22 is coupled to the drift region 100 by means of the barrier region 107 and that at least 5% of the body region 102 in the diode segments 1-22 is directly coupled to the drift region 100, i.e., coupled to the drift region 100 without the barrier region 107. The lateral structure of the barrier layer (and recesses 1071) can be implemented, for example, using a mask used during the implantation process step.

[0139] Now, some examples of the lateral structure of the blocking region 107 will be described with reference to the accompanying drawings:

[0140] For example, according to in Figure 7 In the embodiment illustrated, the blocking region 107 extends only in approximately 50% of the mesa portion 17. In the remaining 50% of the mesa portion 17, the recess 1071 of the blocking region 107 ensures that a pn junction is formed between the body region 102 and the drift region 100.

[0141] For example, according to in Figure 8 In the embodiment shown in the figure, the lateral structure of the blocking region 107 is adapted to the contact plug structure in such a way that the blocking region 107 and the mesa portion 17 of the diode segments 1-22, which is electrically connected to the first load terminal 11 by means of the contact plug structure, overlap laterally.

[0142] exist Figure 8Another optional aspect illustrated in the diagram is that the trench pattern in diode segments 1-22 can also be configured to utilize multiple strip-like trenches 16 (source trenches) extending along the second lateral direction Y (as shown in the diagram). Figure 7 In the case of [the previous case], a trench grid is formed by a plurality of similar strip-shaped trenches 16 (source trenches) extending along the first lateral direction X. The mesa portion 17 is then defined by the grid of the trench grid.

[0143] exist Figure 8 Another optional aspect illustrated in the diagram is that each mesa portion 17 of diode segments 1-22 does not necessarily need to be electrically connected to the first load terminal by means of a contact plug structure. For example, the mesa portion 17 of the diode segment forms a mesa interface region at the front side 110, wherein no more than 90% of the mesa interface region is contacted by a contact plug structure. For example, in Figure 8 In the example, there are 20 mesa portions 17, but only six of these 20 mesa portions are electrically connected to the first load terminal via corresponding contact plugs 117. The other 14 mesa portions 17 (in the exemplary case, those mesa portions surrounding the six mesa portions of the contact) are not electrically connected to the first load terminal 11; therefore, these mesa portions can be considered passive mesa portions because no diode load current can "pass through" these mesa portions in the vertical direction Z.

[0144] Here it should be noted that instead of extending into the countertop portion 18 (e.g., extending into the corresponding contact recess 1110, see...), Figure 10 , Figure 11 The contact plug 111 can additionally or alternatively establish electrical contact between the first load terminal 11 and the platform portion 17 by means of a flat contact achieved at the front side 110.

[0145] For example, according to Figure 9 In the embodiment illustrated, the lateral structure of the blocking region 107 is also adapted to the contact plug structure, for example, in such a way that the blocking region 107 overlaps laterally with the contact plug 111 of the contact plug structure (Variation B) or does not overlap laterally with the contact plug 111 (Variation A). According to both Variation (A) and Variation (B), the lateral structure of the blocking region 107 is defined by a strip-shaped blocking sub-region extending perpendicular to the longitudinal extension of the groove 16 and a recessed strip-shaped segment.

[0146] Additional reference Figure 10Regarding the longitudinal extension of the countertop portion 17 (along the second lateral direction Y), each countertop portion 17 can be separated into one or more first countertop portions 171 equipped with a portion of a blocking region 107 and one or more second countertop portions 172 in which the blocking region 107 is not realized (i.e., one of the recesses 1071 extends therein). Therefore, in Figure 9 and Figure 10 The example shown in the middle is illustrative of the lateral structure of the blocking area 107, which is implemented "parallel" to the groove pattern.

[0147] As indicated above, in addition to or replacing such a "parallel" transverse structure, a transverse structure orthogonal to the groove pattern can be achieved, wherein, for example, strip-shaped blocking sub-regions and recessed strip-shaped segments extend parallel to the longitudinal extension of groove 16. Figure 11 An example of such a lateral structure orthogonal to the groove pattern is illustrated, wherein one or more platform portions 17 are provided with blocking areas 107 along a path in a first lateral direction X, and one or more platform portions 17 are not provided with blocking areas 107 (but are provided with recesses 1071). For example, according to variant (A), two adjacent platform portions 17 are provided with blocking areas 107, and the left (not shown) and right platform portions 17 of the two adjacent platform portions 17 are not provided with blocking areas 107. According to variant (B), three adjacent platform portions 17 are provided with blocking areas 107, and the left (not shown) and right platform portions 17 of the three adjacent platform portions 17 are not provided with blocking areas 107. According to variant (B), four adjacent platform portions 17 are provided with blocking areas 107, and the left (not shown) and right platform portions 17 of the four adjacent platform portions 17 are not provided with blocking areas 107.

[0148] Regarding Figure 11 The effect of the blocking region 107, which can be observed in some embodiments, on the pn junction formed in the mesa portion 17 is explained. For example, due to the increased dopant concentration / dosage (compared to the drift region) of the blocking region 107, the pn junction 1021 formed in the mesa portion 17 where the blocking region 107 is implemented is arranged closer to the front side 110 compared to a pn junction 1021 in the mesa portion 17 where the blocking region 107 is not formed. The difference dZ in the vertical horizontal direction (see variants B and C) can range from 50 nm to 700 nm.

[0149] exist Figures 12 to 14 Further examples of possible lateral structures of the blocking region 107 are schematically illustrated in the figure.

[0150] according to Figure 12In variant (A), the lateral structure of the blocking region 107 is defined by a strip-shaped blocking sub-region extending parallel to the longitudinal extension of the groove 16 (producing a lateral structure orthogonal to the groove pattern) and a recessed strip-shaped segment. Figure 12 In variant (B), the transverse structure of the blocking region 107 is defined by a strip-shaped blocking sub-region that extends perpendicular to the longitudinal extension of the groove 16 (producing a transverse structure parallel to the groove pattern) and a recessed strip-shaped segment. Figure 13 Variation (B) shows a combination in which the structured blocking region 107 appears both orthogonal to and parallel to the groove pattern. This can be achieved, for example, by relatively large rectangular blocking sub-regions separated from each other by a grid-like recessed structure, as also Figure 14 As illustrated in variant (B), the rectangular blocking sub-regions are offset from each other laterally.

[0151] To illustrate the many possibilities of the existence of a laterally structured barrier region 107 Figure 13 and Figure 14 Variation (A) illustrates some examples; for example, the strip-shaped blocking sub-region may extend diagonally or form a circular blocking sub-region. Under the provision that at least 50% of the body region 102 in diode segments 1-22 is coupled to the drift region 100 at least by means of the blocking region 107 and at least 5% of the body region 102 in diode segments 1-22 is coupled to the drift region 100 without the blocking region 107, the illustrated exemplary lateral structure of the blocking region 107 may also be reversed, meaning that the recess 1071 is a sub-region of the blocking region 107 and vice versa.

[0152] For example, according to Figure 15 The embodiment illustrated in the figure can be adapted to the lateral structure of the blocking region 107 with respect to the overall lateral extension of the diode segments 1-22, for example, because the lateral structure of the blocking region 107 in the central region 1-221 of the diode segments 1-22 differs from the lateral structure of the blocking region 107 in the outer peripheral region 1-222 of the diode segments 1-22, which, for example, is connected to the IGBT segments 1-21 and / or the edge termination region 1-3. In the embodiment, the difference in the lateral structure can be such that the region density of the blocking region 107 in the outer peripheral region 1-222 is lower than the region density of the blocking region 107 in the central region 1-221; for example, the percentage share of the body region 102 coupled to the drift region 100 by means of the blocking region 107 in the outer peripheral region 1-222 is lower than the percentage share of the body region 102 coupled to the drift region 100 by means of the blocking region 107 in the central region 1-221. For example, the recess 1071 in the peripheral regions 1-222 may be larger and / or appear more frequently than the recess 1071 in the central region 1-221.

[0153] Additionally or alternatively, the blocking spacing in the peripheral regions 1-222 may be smaller than the blocking spacing in the central regions 1-221; in another embodiment, the difference in the lateral structure may be such that the region density of the blocking region 107 in the peripheral regions 1-222 is higher than that in the central regions 1-221; for example, the percentage of the body region 102 coupled to the drift region 100 by means of the blocking region 107 in the peripheral regions 1-222 is higher than the percentage of the body region 102 coupled to the drift region 100 by means of the blocking region 107 in the central regions 1-221. For example, the recess 1071 in the peripheral regions 1-222 may be smaller and / or appear less frequently than the recess 1071 in the central regions 1-221.

[0154] In addition to or as a replacement, the blocking spacing in the outer perimeter area 1-222 may be smaller than the blocking spacing in the central area 1-221.

[0155] In another embodiment, the recesses 1071 in the blocking area 107 may not be distributed in a regular pattern, but rather are distributed non-uniformly in terms of distance and / or size.

[0156] A method for processing a power semiconductor device is also provided herein. Embodiments of the method include forming: an active region having a diode segment; an edge-terminating region surrounding the active region; a semiconductor body having a front side and a back side; 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, wherein the diode segment is configured to conduct diode load current between the first load terminal and the second load terminal; a drift region of a first conductivity type formed in the semiconductor body and extending into the diode segment; a plurality of trenches arranged in the diode 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 body region of a second conductivity type formed in the mesa portion of the semiconductor body and electrically connected to the first load terminal; and a first conductivity blocking region between the body region and the drift region in the diode segment, wherein the blocking region has a dopant concentration at least 100 times greater than the average dopant concentration of the drift region and has a dopant dose greater than that of the body region. The blocking region has a lateral structure, according to which at least 50% of the body region in the diode segment is coupled to the drift region at least by means of the blocking region; and at least 5% of the body region in the diode segment is coupled to the drift region in the absence of the blocking region.

[0157] An exemplary embodiment of this method corresponds to the embodiment of the power semiconductor device 1 described above. In one embodiment, a mask is used to form the barrier region 107 during an implantation process step (e.g., phosphorus implantation). The mask can be structured to achieve a lateral structure of the barrier region 107 with recesses, examples of which have been explained above. For example, the barrier region 107 is formed before the body region 102 is formed.

[0158] The embodiments relating to power semiconductor devices such as RC IGBTs and diodes, and the corresponding processing methods, have been explained above. It is suggested that a blocking region 107 be introduced in the diode section 1-22 of the diode or, correspondingly, the RC IGBT. For example, the dopant dose of the blocking region 107 is sufficiently high to limit any hole injection into the drift region 100 (e.g., higher than 2 × 10⁻⁶). 13 cm -2 Holes can be injected into device 1 by means of the recess 1071 opening the blocking region 107. Since the electron path is not significantly suppressed by the additional blocking region 107, a portion of the electron current passes through the blocking region 107. The hole current is injected only as a portion of the electron current flowing through the recess 1071. By structuring the blocking region 107 by means of the recess 1071, the plasma concentration is relatively constant in the transverse cross-section, and therefore the current density is not significantly lower in the section in which the blocking region 107 is implemented. Furthermore, by means of the recess 1071 "opening" the blocking region 107 with a specific region ratio, the effective anode efficiency of device 1 can be precisely controlled. A potential benefit of such a transverse structure of the blocking region 107 is the flexibility in adjusting the current dependence of the emitter efficiency. For example, emitter-controlled diodes typically experience relatively high emitter efficiencies at low current densities, which can be critical for current jumps during reverse recovery. By introducing a transversely structured blocking region 107, the total anode-side plasma level can be reduced at low current densities, while maintaining the same plasma level under nominal conditions.

[0159] The embodiments relating to power semiconductor devices such as RC IGBTs and diodes, and the corresponding processing methods have been explained above.

[0160] For example, these power semiconductor devices are based on silicon (Si). Therefore, the single-crystal semiconductor region or layer (e.g., semiconductor body 10 and its regions / zones, such as regions, etc.) can be single-crystal Si regions or Si layers. In other embodiments, polycrystalline silicon or amorphous silicon can be used.

[0161] 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.)

[0162] 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.

[0163] 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.

[0164] 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. A power semiconductor device, comprising: - Active region with diode segments; - Termination region surrounding the edge of the active region; - Semiconductor body, having a front side and a back side; - A first load terminal on the front side of the semiconductor body and a second load terminal on the back side of the semiconductor body, wherein a diode segment is configured to conduct diode load current between the first load terminal and the second load terminal; - A drift region of the first conductivity type is formed in the semiconductor body and extends into the diode segment; - Multiple trenches are arranged in the diode section, 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 body region of a second conductivity type is formed in the mesa portion of the semiconductor body and is electrically connected to the first load terminal; - In the diode segment, a first conductive blocking region exists between the body region and the drift region, wherein the blocking region has a dopant concentration at least 100 times greater than the average dopant concentration of the drift region and has a dopant dose greater than that of the body region, wherein the blocking region has a lateral structure, according to which: At least 50% of the body region in the diode segment is coupled to the drift region at least by means of the blocking region; and At least 5% of the body region in the diode segment is coupled to the drift region in the absence of a blocking region.

2. The power semiconductor device according to claim 1, wherein, The lateral structure of the blocking region overlaps laterally with at least 70% of the horizontal cross-sectional area of ​​the diode segment, wherein the body region of the diode segment is coupled to the drift region at least by means of the blocking region in which the lateral overlap is established.

3. The power semiconductor device according to claim 1 or 2, wherein, The blocking region includes a recess that overlaps laterally by at least 5% with the body region of the diode segment that is coupled to the drift region in the absence of a blocking region.

4. The power semiconductor device according to claim 3, wherein, - The lateral distance between two adjacent recesses is defined by the blocking spacing of the pattern of the blocking area, which defines the lateral structure of the blocking area; - The lateral distance between two adjacent trenches is defined by the trench spacing of the trench pattern in the diode segment; - The minimum value of the barrier spacing is greater than the minimum value of the trench spacing.

5. The power semiconductor device according to claim 4, wherein, The minimum value of the blocking spacing is less than 50% of the thickness of the semiconductor body, which is the distance from the front side to the back side in the vertical direction within the diode segment.

6. The power semiconductor device according to claim 4 or 5, wherein, The lateral extension direction of the blocking area is arranged to be orthogonal to the lateral extension of the groove pattern.

7. The power semiconductor device according to claim 4 or 5, wherein, The lateral extension direction of the blocking area is arranged to be parallel to the lateral extension of the groove pattern.

8. The power semiconductor device according to claim 1 or 2, wherein, At least 50% of the trench electrodes in the diode segment are electrically connected to the first load terminal.

9. The power semiconductor device according to claim 1 or 2, further comprising a contact plug structure having a contact plug, wherein, Each contact plug is configured to establish contact with the corresponding mezzanine portion in order to electrically connect the corresponding mezzanine portion to the first load terminal.

10. The power semiconductor device according to claim 9, wherein, Each contact plug extends vertically from the front into the corresponding platform portion.

11. The power semiconductor device according to claim 9, wherein, The countertop portion forms a countertop interface area on the front side, wherein no more than 90% of the countertop interface area is contacted by a contact plug structure.

12. The power semiconductor device according to claim 1 or 2, wherein, The horizontal cross-sectional area of ​​the diode segment has a minimum lateral extension that is at least equal to the thickness of the semiconductor body.

13. The power semiconductor device according to claim 1 or 2, further comprising an IGBT segment in the active region, the IGBT segment being configured to conduct a forward load current between a first load terminal and a second load terminal, and wherein, The diode load current is the reverse load current of the device, and each of the plurality of trenches, drift regions, and body regions extends into the IGBT segment.

14. The power semiconductor device according to claim 13, wherein, At least 90% of the body region in the IGBT segment is coupled to the drift region in the absence of a blocking region.

15. The power semiconductor device according to claim 13, wherein, Regarding the volume of the active region, the ratio between the total IGBT segment and the total diode segment is greater than 1.5:

1.

16. The power semiconductor device according to claim 13, wherein, The IGBT segment further includes an IGBT emitter region of a second conductivity type, which is electrically connected to the second load terminal and coupled to the drift region.

17. The power semiconductor device of claim 13, further comprising a diode cathode region of a first conductivity type in the diode segment, the diode cathode region being electrically connected to a second load terminal and coupled to a drift region.

18. A method for processing a power semiconductor device, comprising forming the following: - Active region with diode segments; - Termination region surrounding the edge of the active region; - Semiconductor body, having a front side and a back side; -A first load terminal on the front side of the semiconductor body and a second load terminal on the back side of the semiconductor body, wherein... The diode section is configured to conduct diode load current between the first load terminal and the second load terminal; - A drift region of the first conductivity type is formed in the semiconductor body and extends into the diode segment; - Multiple trenches are arranged in the diode section, 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 body region of a second conductivity type is formed in the mesa portion of the semiconductor body and is electrically connected to the first load terminal; - In the diode segment, a first conductive blocking region exists between the body region and the drift region, wherein the blocking region has a dopant concentration at least 100 times greater than the average dopant concentration of the drift region and has a dopant dose greater than that of the body region, wherein the blocking region has a lateral structure, according to which: At least 50% of the body region in the diode segment is coupled to the drift region at least by means of the blocking region; and At least 5% of the body region in the diode segment is coupled to the drift region in the absence of a blocking region.

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