RC IGBT and method of operating RC IGBT

Abstract

The invention relates to an RC IGBT and a method of operating the RC IGBT. The RC IGBT (1) comprises, in a single chip, an active region (1-2) configured to conduct both a forward load current and a reverse load current between a first load terminal (11) of a front side (110) of a semiconductor body (10) of the RC IGBT (1) and a second load terminal (12) of a rear side (120) of the semiconductor body (10). The active region (1-2) is separated into at least: only an IGBT region (1-21), at least 90% of which is configured to conduct only a forward load current based on a first control signal (13-21); an RC IGBT region (1-22), at least 90% of which is configured to conduct a reverse load current and to conduct a forward load current based on a second control signal (13-22); and a mixing zone (1-24), at least 90% of which is configured to conduct a forward load current based on both the first control signal (13-21) and the second control signal (13-22).

Description

Technical Field

[0001] The present description relates to embodiments of an RC IGBT, and to embodiments of operating the RC IGBT. Background Art

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

[0003] A power semiconductor device typically includes a semiconductor body configured to conduct a forward load current along a load current path between two load terminals of the device. Typically, the load current is conducted by means of an active region of the power semiconductor device. The active region is typically surrounded by an edge termination region that is terminated by the edge of the chip.

[0004] In the case of a controllable power semiconductor device (e.g., a transistor), the load current path can be controlled by means of an insulated electrode (usually referred to as a gate electrode). For example, upon receiving a corresponding control signal from a driver unit, e.g., via a control terminal of the device, the control electrode can set the power semiconductor device in one of a forward conducting state and a forward blocking state.

[0005] Additionally, some devices provide reverse load current capability, where the active region of the semiconductor body is further configured to conduct a reverse load current along a reverse load current path between two load terminals of the device.

[0006] For example, an RC (reverse current) IGBT is a representative of such a device. In an RC IGBT, a single chip houses an IGBT structure and a diode structure, wherein not only the IGBT (i.e., forward load current) can be controlled based on the gate signal, but also the characteristics of the diode behavior (i.e., reverse load current) can be affected. The present specification relates to such an RC IGBT.

[0007] Compared to a diode and an IGBT on separate chips connected in anti-parallel to each other, an RC IGBT exhibits some advantages, for example in terms of turn-on losses, reverse recovery losses and / or thermal behavior, but may also be more complex to control. Summary of the invention

[0008] The subject matter of the independent claims is presented. Features of exemplary embodiments are defined in the dependent claims.

[0009] According to a first embodiment, an RC IGBT includes an active region in a single chip, the active region being configured to conduct both a forward load current and a reverse load current between a first load terminal on a front side of a semiconductor body of the RC IGBT and a second load terminal on a rear side of the semiconductor body. The active region is separated into at least: an IGBT-only region, at least 90% of which is configured to conduct only a forward load current based on a first control signal; an RC IGBT region, at least 90% of which is configured to conduct a reverse load current and conduct a forward load current based on a second control signal; and a mixed region, at least 90% of which is configured to conduct a forward load current based on both the first control signal and the second control signal.

[0010] According to another embodiment, a method of operating the RC IGBT according to the first embodiment is presented. The method includes: controlling the RC IGBT based on a first control signal and a second control signal.

[0011] Those skilled in the art will recognize additional features and advantages upon reading the following detailed description, and upon viewing the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The various parts in the drawings are not necessarily to scale, but the emphasis is on illustrating the principles of the present invention. In addition, in the drawings, like reference numerals designate corresponding parts. In the drawings:

[0013] Figure 1 schematically and exemplarily illustrates a horizontally projected segment of a RC IGBT according to one or more embodiments;

[0014] Figure 2 schematically and exemplarily illustrates a horizontally projected section of an active area of ​​an RC IGBT according to one or more embodiments;

[0015] Figure 3 schematically and exemplarily illustrates a section of a vertical cross section of an RC IGBT according to one or more embodiments;

[0016] Figure 4 schematically and exemplarily illustrate a method of operating an RC IGBT according to one or more embodiments; and

[0017] Figure 5 schematically and exemplarily illustrate theoretical independent output characteristics of an RC IGBT region and a hybrid region of an RC IGBT according to one or more embodiments;

[0018] Figure 6 schematically and exemplarily illustrates a section of a vertical cross section of an RC IGBT according to one or more embodiments; and

[0019] Figure 7 A section of a vertical cross section of an RC IGBT according to one or more embodiments is schematically and exemplarily illustrated. DETAILED DESCRIPTION

[0020] In the following detailed description, reference is made to the accompanying drawings, which form a part hereof, and in which is shown by way of illustration specific embodiments in which the invention may be practiced.

[0021] In this regard, directional terms such as "top", "bottom", "below", "front", "behind", "rear", "first", "last", "above", etc. may be used with reference to the orientation of the drawings being described. Because the various parts of the embodiments can be placed in many different orientations, the directional terms are used for illustrative purposes and are in no way limiting. It should be understood that other embodiments may be used and structural or logical changes may be made without departing from the scope of the present invention. Therefore, the following detailed description should not be understood in a limiting sense, and the scope of the present invention is defined by the appended claims.

[0022] Reference will now be made in detail to various embodiments, one or more examples of which are illustrated in the accompanying drawings. Each example is provided as an explanation, and each example is not intended to be a limitation of the present invention. For example, a feature illustrated or described as part of one embodiment can be used on other embodiments or used in conjunction with other embodiments to produce another embodiment. It is intended that the present invention includes such modifications and variations. Examples are described using specific language, which should not be interpreted as limiting the scope of the appended claims. The accompanying drawings are not drawn to scale and are for illustrative purposes only. For clarity, the same elements or manufacturing steps have been designated by the same reference numerals in different drawings if not otherwise indicated.

[0023] As used in this specification, the term "horizontal" is intended to describe an orientation substantially parallel to a horizontal surface of a semiconductor substrate or semiconductor structure. This can be, for example, a surface of a semiconductor wafer or 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.

[0024] As used in this specification, the term "vertical" is intended to describe an orientation that is substantially arranged perpendicular to a 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 may 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 the "vertical direction Z".

[0025] In this specification, n-doping is referred to as “first conductivity type” and p-doping is referred to as “second conductivity type.” Alternatively, the opposite doping relationship can be adopted, so that the first conductivity type can be p-doped and the second conductivity type can be n-doped.

[0026] In the context of this specification, the terms "in ohmic contact", "in electrical contact", "ohmically connected", and "electrically connected" are intended to describe that a low-ohmic electrical connection or a low-ohmic current path exists between two regions, sections, zones, portions or parts 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 part of a semiconductor device, where "low ohmic" may mean that the characteristics of the respective contact are essentially unaffected by ohmic resistance. In addition, in the context of this specification, the term "in contact" is intended to describe that a direct physical connection exists between two elements of the respective semiconductor device; for example, a transition between two elements in contact with each other may not include another intermediate element, etc.

[0027] In addition, in the context of this specification, if not otherwise indicated, the term "electrically isolated" is used with the generally valid understanding of the term "electrically isolated", and thus, the term "electrically isolated" is intended to describe that two or more components are arranged to be separated from each other and there is no ohmic connection connecting those components. However, components that are electrically isolated from each other may still be coupled to each other, for example mechanically and / or capacitively and / or inductively and / or electrostatically (for example, in the case of a junction). As an example, two electrodes of a capacitor may be electrically isolated from each other and, at the same time, mechanically and capacitively coupled to each other, for example, by means of insulation (for example, a dielectric).

[0028] The specific embodiments described in this specification relate to RC IGBTs, for example, power semiconductor devices that can be used in power converters or power supplies. Therefore, in embodiments, such RC IGBTs can be configured to carry a load current to be fed to a load and / or provided by a power supply. For example, the RC IGBT may include one or more active power semiconductor unit cells, such as a monolithically integrated diode cell, a derivative of a monolithically integrated diode cell, a monolithically integrated transistor cell (e.g., a monolithically integrated IGBT cell), and / or a derivative thereof. Such a diode / transistor cell may be integrated in a power semiconductor module. A plurality of such cells may constitute a cell field, which is arranged in an active region of a power semiconductor device.

[0029] The term "blocking state" of the RC IGBT may refer to a condition when the RC IGBT is in a state configured to block the flow of a load current while an external voltage is applied. More particularly, the RC IGBT may be configured to block a forward load current through the RC IGBT while a forward voltage bias is applied. In contrast, the RC IGBT may be configured to conduct a forward load current in a "conducting state" of the RC IGBT while a forward voltage bias is applied. The transition between the blocking state and the conducting state may be controlled by a control electrode, or more particularly, by the potential of the control electrode. The electrical characteristics may of course only apply within a predetermined operating range of an external voltage and current density within the RC IGBT. The term "forward biased blocking state" may therefore refer to a condition in which the RC IGBT is in a blocking state while a forward voltage bias is applied.

[0030] As used in this specification, the term "RC IGBT" is intended to describe an RC IGBT on a single chip having high voltage blocking and / or high current carrying capabilities. In other words, such an RC IGBT is intended for: high currents, typically in the ampere range, such as up to tens or hundreds of amperes; and / or high voltages, typically above 100V, more typically 400V and above, such as up to at least 1200V or even higher, such as up to at least 3kV, or even up to 10kV or higher, depending on the respective application.

[0031] For example, as used in this specification, the term "RC IGBT" does not refer to a logic semiconductor device used, for example, to store data, calculate data, and / or other types of semiconductor-based data processing.

[0032] For example, the RC IGBT described below may be a single semiconductor chip exhibiting, for example, a stripe cell configuration (or a honeycomb / needle cell configuration) and can be configured for use as a power component in low voltage, medium voltage, and / or high voltage applications.

[0033] Figure 1 Schematically and exemplarily illustrates a horizontally projected section of an RC IGBT 1 according to one or more embodiments. Figure 3 The vertical section shown in the figure and the Figure 2 A more detailed illustration of an exemplary active region 1-2 of FIG.

[0034] The RC IGBT 1 comprises a semiconductor body 10 coupled to a first load terminal at a front side (also referred to as the first side) 110 and to a second load terminal 12 at a rear side (also referred to as the back side) 120, which is opposite to the front side 110 with respect to a vertical direction Z. The semiconductor body 10 is part of a single chip comprising an active area 1-2 configured to conduct both a forward load current and a reverse load current between the first load terminal 11 and the second load terminal 12 at the back side 120.

[0035] The vertical thickness d of the semiconductor body 10 may be defined as the distance between the front side 110 and the back side 120 along the vertical direction Z, measured, for example, at the horizontal center of the active region 1 - 2 .

[0036] The RC IGBT 1 may exhibit a vertical configuration according to which both the forward load current and the reverse load current flow substantially parallel to the vertical direction Z.

[0037] For example, the first load terminal 11 may be a source (or emitter) terminal, and the second load terminal 12 may be a drain (collector) terminal.

[0038] The active region 1-1 is surrounded by an edge termination region 1-3 which is terminated by a chip edge 1-4. In this document, the terms "active region" (sometimes also referred to as "element field"), "edge termination region" and "chip edge" have the technical meanings that a skilled person usually associates with them in the context of RC IGBTs and are therefore not explained in more detail.

[0039] According to the embodiments disclosed herein, the active region 1 - 2 of the RC IGBT 1 is separated into at least an IGBT-only region 1 - 21 , a RC IGBT region 1 - 22 , and a mixed region 1 - 24 .

[0040] For example, only at least 90% of the IGBT regions 1-21 are configured to conduct only forward load current based on the first control signal 13-21. The share of at least 90% can even be greater than 90%, for example, at least 95%, at least 98%, or even equal to 100%. In other words, only the IGBT region 1-21 is configured not to contribute to the reverse load current carrying capability.

[0041] For example, at least 90% of the RC IGBT regions 1-22 are configured to conduct the reverse load current and, for example, conduct the forward load current only based on the second control signal 13-22. The share of at least 90% can be even greater than 90%, for example, at least 95%, at least 98%, or even equal to 100%. The RC IGBT regions 1-22 are configured in an embodiment not to control the forward load current based on the first control signal 13-21, but to control the forward load current only based on the second control signal 13-22. For example, at least 90% or at least 95% or at least 98% or even 100% of the RC IGBT regions 1-22 may not have a control trench electrode connected to the first control signal 13-21.

[0042] For example, at least 90% of the hybrid region 1-24 is configured to conduct a forward load current based on both the first control signal 13-21 and the second control signal 13-22. The at least 90% share can be even greater than 90%, for example, at least 95%, at least 98%, or even equal to 100%. For example, the hybrid region 1-24 exhibits an RC IGBT configuration or an IGBT configuration.

[0043] According to one or more embodiments, the hybrid region 1-24 is configured to conduct a forward load current both during the forward conduction phase and the forward desaturation phase of the RC IGBT 1. This can result in increased performance, for example, in improved over-current disconnection robustness, because the current during disconnection is not only carried by the RC IGBT region 1-22, but is also distributed within both the RC IGBT region 1-22 and the hybrid region 1-24. This can result in a reduced current density at disconnection.

[0044] Additionally, the active region 1-2 may include a diode-only region 1-23, which will be explained in more detail below.

[0045] It should be understood that Figure 2 The arrangement of the IGBT-only region 1-21, the RC IGBT region 1-22, the hybrid region 1-24 and the optional diode-only region 1-23 shown in is only exemplary. For example, the regions 1-21, 1-22, 1-24 and 1-23 do not necessarily need to be continuous regions, but can also be composed of spatially distributed sub-regions. In addition, instead of being arranged in the center, the IGBT-only region 1-21 can be arranged alternatively or additionally in the peripheral part of the active region 1-2. For example, the regions 1-21, 1-22, 1-24 and (optionally) 1-23 can exhibit a rectangular lateral periphery and be arranged in the active region 1-2 according to a stripe pattern. The latter variant can facilitate the supply of control signals to the regions 1-21, 1-22 and 1-24.

[0046] A skilled person may size and arrange the three regions 1-21, 1-22, and 1-23 within the active region 1-2 according to the specified characteristics of the RC IGBT 1 and further circumstances.

[0047] In an embodiment, the second control signal 13-22 is different from the first control signal 13-21. For example, the second control signal 13-22 is generated separately from the first control signal 13-21. Thus, the control of the forward load current in the IGBT region 1-21 alone can be independent of the control of the forward load current in the RC IGBT region 1-22. However, in the hybrid region 1-24, the forward load current is controlled based on both the first control signal 13-21 and the second control signal 13-22.

[0048] In an embodiment, the active region 1-2 is separated into at least: a) different IGBT-only regions 1-21, which only carry forward load current (and no reverse load current) and are controlled based on a first control signal 13-21; b) different RC IGBT regions 1-22, which carry both forward and reverse load currents and are controlled based on a second control signal 13-22, which may be independent of the first control signal 13-21; and c) mixed regions 1-24, which may exhibit an IGBT configuration or an RC IGBT configuration, and are controlled based on both the first control signal 13-21 and the second control signal 13-22.

[0049] In an embodiment, the RC IGBT region 1 - 22 is configured to conduct a reverse load current regardless of the second control signal 13 - 22 .

[0050] The IGBT-only region 1-21 and the RC IGBT region 1-22 may occupy a large portion of the active region 1-2; for example, the IGBT-only region 1-21 and the RC IGBT region 1-22 may be equal to at least 80% of the active region 1-2. The remainder of the active region 1-2 may be occupied, for example, by the hybrid region 1-24 and the optional diode-only region 1-23. For example, up to 70% of the active region 1-2 may be occupied by the IGBT-only region 1-21, up to 25% of the active region 1-2 may be occupied by the RC-IGBT region 1-22, and up to 10% of the active region 1-2 may be occupied by the hybrid region 1-23. However, these figures may be only exemplary, and as indicated above, the skilled person may determine the dimensions for the three regions 1-21, 1-22 and 1-23 according to the specified characteristics of the RC IGBT 1 and further circumstances.

[0051] Each of the IGBT-only region 1-21, the RC IGBT region 1-22 and the hybrid region 1-24 may exhibit a total lateral extension of at least 20% of the vertical thickness d of the semiconductor body 10. One or more of the total lateral extensions may be even greater, such as at least 70%, 80% or even more than 100% of the vertical thickness d of the semiconductor body 10. For example, the IGBT-only region 1-21 is the largest region of the three regions 1-21, 1-22 and 1-24 and has a total lateral extension of at least 100% of the vertical thickness d of the semiconductor body 10. For example, the RC IGBT region 1-22 is the second largest region of the three regions 1-21, 1-22 and 1-24 and has a total lateral extension of at least 70% of the vertical thickness d of the semiconductor body 10. For example, the hybrid region 1-24 is the smallest of the three regions 1-21, 1-22 and 1-24 and has a total lateral extension of at least 20% of the vertical thickness d of the semiconductor body 10. If only the diode region 1-23 is provided, only the diode region 1-23 is smaller than each of the three regions 1-21, 1-22 and 1-24 and has a total lateral extension of at least 10% of the vertical thickness d of the semiconductor body 10. However, in case the RC IGBT 1 is configured for very high blocking voltages and therefore exhibits a correspondingly large vertical thickness d of the semiconductor body 10, the lateral extension may be smaller (relative to the vertical thickness d of the semiconductor body 10).

[0052] In an embodiment, only the IGBT region 1-21, the RC IGBT region 1-22 and the hybrid region 1-24 are spatially separated from each other. For example, there is no spatial overlap between the regions.

[0053] In addition, the IGBT-only region 1 - 21 can be a first continuous region, the RC IGBT region 1 - 22 can be a second continuous region, and the mixed region 1 - 24 can be a third continuous region, wherein the three continuous regions can be arranged separately from each other.

[0054] For example, at least 90% of the optional diode-only region 1-23 is configured to conduct only reverse load current (but not, for example, forward load current). In an embodiment, the diode-only region 1-23 is not subject to the influence of the first control signal 13-21 or the second control signal 13-22. For example, the diode-only region 1-23 does not include any control trench. In addition, it can be provided that the diode-only region 1-23 does not include any semiconductor source region 101 electrically connected to the first load terminal 11.

[0055] As indicated above, the skilled person may size and arrange the three regions 1-21, 1-22 and 1-24 (and the optional diode-only region 1-23) within the active region 1-2 according to the specified characteristics of the RC IGBT 1. Furthermore, the expression "at least 90%" used in the context of describing these regions shall mean that the main purpose of these regions is to conduct only forward load current (in the case of the IGBT-only region 1-21) or only reverse load current (in the case of the optional diode-only region 1-23) or both forward and reverse load current (in the case of the RC IGBT region 1-22). The same applies to the mixed region 1-24, which may, for example, present an IGBT configuration (forward load current only) or an RC IGBT configuration (both forward and reverse load current).

[0056] In an embodiment, the characteristics of the zones may deviate in a correspondingly smaller sub-portion of 10% or less of the zones, for example, in a transition zone where one of the zones 1-21, 1-22, 1-23 and 1-24 adjoins another of these zones. This transition will be described in more detail below.

[0057] We will now refer in more detail to Figure 3 , Figure 3 A section of a vertical cross section of an exemplary embodiment of an active region 1-2 is shown, the active region 1-2 including an IGBT-only region 1-21, an RC IGBT region 1-22, a hybrid region 1-24, and a diode-only region 1-23. It is again emphasized that the diode-only region 1-23 is optional. In other embodiments where the diode-only region 1-23 is not provided, the reverse load current is completely carried by the RC IGBT region 1-22.

[0058] As shown in the figure, the active region 1-2 exhibits a vertical configuration, the first load terminal 11 is arranged at the semiconductor body front side 110 and the second load terminal 12 is arranged at the semiconductor body back side 120. The first load terminal 11 and the second load terminal 12 may be shared by each of the IGBT-only region 1-21, the RC IGBT region 1-22, the hybrid region 1-24, and the diode-only region 1-23.

[0059] With respect to the vertical direction Z, a drift region 100 of the first conductivity type may form a major central portion of the semiconductor body 10. Such a drift region 100 may be shared by each of the IGBT-only region 1-21, the RC IGBT region 1-22, the hybrid region 1-24, and by the diode-only region 1-23 if only the diode region 1-23 exists.

[0060] The active region 1 - 2 may be configured at both the front side 110 and the back side 120 according to the distribution of the IGBT-only region 1 - 21 , the RC IGBT region 1 - 22 , the hybrid region 1 - 24 , and the diode-only region 1 - 23 .

[0061] For example, with respect to the back side 120, a back side emitter 108 coupled to the drift region 100 is arranged, the back side emitter 108 being in electrical connection with the second load terminal 12, wherein the back side emitter 108 is configured according to the active region 1-2 being separated into at least only IGBT region 1-21, RCIGBT region 1-22, hybrid region 1-24 and only diode region 1-23 (if only diode region 1-23 is implemented).

[0062] In an embodiment, the back side emitter 108 may be configured to have:

[0063] - a first section 108 - 21 of the second conductivity type, located in the portion of the active area 1 - 2 where only the IGBT area 1 - 21 exists;

[0064] - a second section 108-22, located in the portion of the active region 1-2 where the RC IGBT region 1-22 exists, including both a first sub-section 108-221 of the first conductivity type and a second sub-section 108-222 of the second conductivity type;

[0065] a fourth section 108-24 located in a portion of the active region 1-2 where the mixed region 1-24 is present, wherein the fourth section 108-24 is configured in terms of conductivity type according to at least one of the first section 108-21 and the second section 108-22;

[0066] - and optionally, if only the diode region 1-23 is implemented, a third section 108-23 of the first conductivity type, said third section 108-23 being located in the portion of the active region 1-2 where only the diode region 1-23 is present.

[0067] For example, the first segment 108 - 21 of the backside emitter 108 has only the second conductivity type. That is, in an embodiment, the first segment 108 - 21 does not include any portion of the first conductivity type.

[0068] In addition, the first section 108 - 21 of the back side emitter 108 may exhibit a total lateral extension thereof along the first lateral direction X and at a certain vertical level of at least 2*10 15 cm -3 The average dopant concentration can be even greater, for example, equal to at least 2*10 16 cm -3 or 1*10 17 cm -3 .

[0069] That is, in an embodiment, at a certain vertical level and along at least one of the first lateral direction X and the second lateral direction Y, the first segment 108-21 of the back side emitter 108 may exhibit a variation in dopant concentration. For example, based on VLD (lateral dopant concentration variation), certain characteristics of the back emitter 108 (e.g., emitter efficiency) may be adjusted in only the IGBT region 1-21. This may allow the temperature distribution within the semiconductor body 10 to be uniform. In the example, in a sub-segment of the first segment 108-21 near 1-24, the dopant concentration is less than 80% of the dopant concentration in the center of the first segment 108-21. This design may allow the diagonal current flow from the front side of the mixed region 1-24 toward the first segment 108-21 to be suppressed during the desaturation phase. According to an embodiment, among all p-doped segments of the back side emitter 108, including p ++ Stripes and p - The stripe pattern has a stripe width that is less than 30% of the thickness d of the semiconductor body 10. ++ The dopant concentration and p - The ratio of the dopant concentrations of the stripes may be equal to at least two, or equal to at least five, or equal to at least ten.

[0070] In addition, the first section 108-21 can be displaced relative to the RC IGBT region 1-22 by, for example, at least the mixed region 1-24. In other words, the mixed region 1-24 can be arranged between the IGBT-only region 1-21 and the RC IGBT region 1-22.

[0071] Now, with regard to the second section 108-22 of the back side emitter 108, in an embodiment, each of the first sub-sections 108-221 of the first sub-sections 108-221 of the second section 108-22 of the back side emitter 108 exhibits, for its respective total lateral extension along the first lateral direction X and at a certain vertical level, at least 1*10 18 cm -3 The average dopant concentration can be even greater, for example, equal to at least 5*10 18 cm -3 or 1*10 19 cm -3 .

[0072] In addition, each of the second subsections 108-222 can be displaced relative to the diode region 1-23 by a second distance d2 of at least 20% of the thickness d of the semiconductor body 10. For example, based on the second distance d2, it can be ensured that, during the diode reverse recovery process, outside the second subsection 108-222, there is no injection of holes or only a limited injection of holes. In an embodiment, the third section 108-23 of the back emitter 108 can include one or more p-doped regions to cause the injection of holes during the diode reverse recovery phase.

[0073] The third section 108-23 of the back side emitter region 108 can be a region of only the first conductivity type. In another embodiment, the third section 108-23 may include (not shown) a sub-section of the second conductivity type that is also electrically connected to the second load terminal, for example, a "p-short", similar to the "n-short" / first sub-section 108-221 of the first conductivity type in the second section 108-22 of the back side emitter 108.

[0074] As explained above, the hybrid region 1-24 can exhibit an IGBT configuration or an RC IGBT configuration.Thus, the fourth section 108-24 of the backside emitter 108 can be configured similarly to the first section 108-21 (ie, an IGBT configuration) or similarly to the second section 108-22 (ie, an RC IGBT configuration).

[0075] In an embodiment, as shown in the figure, in a portion of the fourth section 108-24 adjacent to the IGBT region 1-21 only, the fourth section 108-24 can (only) have the second conductivity type. That is, in an embodiment, in said portion, the fourth section 108-24 does not include any region of the first conductivity type. In addition, in said portion, the fourth section 108-24 of the back emitter 108 can exhibit at least 2*10 for its total lateral extension along the first lateral direction X and at a certain vertical level. 15 cm -3 The average dopant concentration can be even greater, greater, for example, equal to at least 2*10 16 cm -3 or 1*10 17 cm -3. Moreover, like the first section 108 - 21 , in an embodiment, the fourth section 108 - 24 of the back side emitter 108 may exhibit a variation of dopant concentration in the portion at a certain vertical level and along at least one of the first lateral direction X and the second lateral direction Y. For example, based on VLD (lateral dopant concentration variation), certain characteristics of the back side emitter 108 , such as emitter efficiency, may be adjusted in only the IGBT region 1 - 21 , as explained above.

[0076] On the other hand, in an embodiment and as shown in the figure, in a portion of the fourth section 108-24 adjacent to the RC-IGBT region 1-22, the fourth section 108-24 can be configured as a second section 108-22. In the portion, the fourth section 108-24 can include both a first sub-section 108-241 of a first conductivity type and a second sub-section 108-242 of a second conductivity type. The description of the first sub-section 108-221 and the second sub-section 108-222 of the second section 108-2 provided above by way of example can be equally applicable to the first sub-section 108-241 and the second sub-section 108-242 of the fourth section 108-24. Even the first section 108-21 can also exhibit a first sub-section (not shown) close to a transition toward the mixed region 1-24. Such a sub-section not shown can have a lateral extension equal to the thickness d of the semiconductor body 10, or even up to twice the thickness d.

[0077] In another embodiment, the RC IGBT 1 further comprises a field stop zone 107 of the first conductivity type, the field stop zone 107 being arranged to contact both the drift region 100 and each of the first section 108-21, the second section 108-22, the fourth section 108-24 and the third section 108-23 (if the third section 108-23 is implemented) of the back side emitter 108. The dopant concentration of the field stop zone 107 can be greater than the dopant concentration of the drift region 100.

[0078] As shown in the figure, the thickness of the first segment 108-21, the second segment 108-22, the fourth segment 108-24, and the third segment 108-23 (if the third segment 108-23 is implemented) of the back side emitter 108 can vary. For example, the third segment 108-23 of the back side emitter 108 in the optional diode-only region 1-23 may be thinner than the remaining segments 108-21, 108-22, and 108-24 of the back side emitter 108. The lower thickness of the back side emitter 108 can reduce its emitter efficiency, which can allow for lower switching losses (e.g., diode reverse recovery losses). In the case of a reduced thickness of the back side emitter 108, the field stop zone 107 may be thicker than the rest of it that laterally overlaps with the segments 108-21, 108-22, and 108-24 of the back side emitter 108. The described configuration of the backside emitter 108 and the field stop layer 107 in the optional diode-only region 1 - 23 may extend into the RC IGBT region 1 - 22 along a path corresponding to the distance d2 , as shown in the figure.

[0079] As indicated above, the configuration of the active areas 1-2 may also reflect at the front side 110 that the active areas 1-2 are separated into at least only IGBT areas 1-21, RC IGBT areas 1-22, hybrid areas 1-24 and only diode areas 1-23 (if only diode areas 1-23 are implemented).

[0080] For example, the RC IGBT 1 also includes a trench-mesa pattern at the front side 110, wherein the trench-mesa pattern is configured according to the separation of the active area 1-2 into at least only IGBT area 1-21, RC IGBT area 1-22, hybrid area 1-24 and only diode area 1-23 (if only diode area 1-23 is implemented). This will be described in more detail below:

[0081] An exemplary configuration of the trench-mesa pattern on the front side 110 is shown in Figure 3 The illustrated trench-mesa pattern includes a first control trench 14-21 configured to receive a first control signal 13-21 and a second control trench 14-22 configured to receive a second control signal 13-22. In terms of structure, the first control trench 14-21 and the second control trench 14-22 may be configured similarly.

[0082] For example, the IGBT-only region 1-21 includes a plurality of first control trenches 14-21, but optionally does not include any second control trenches 14-22. That is, in an embodiment, the IGBT-only region 1-21 is controlled based only on the first control trenches 14-21, because no second control trenches 14-22 exist in the IGBT-only region 1-21.

[0083] In addition, the RC-IGBT region 1-22 may include a plurality of second control trenches 14-22, but may optionally not include any first control trenches 14-21. That is, in an embodiment, the RC IGBT region 1-22 is controlled based only on the second control trenches 14-22 because no first control trenches 14-21 exist in the RC IGBT region 1-22.

[0084] In addition, the hybrid region 1-24 may include both a plurality of first control trenches 14-21 and a plurality of second control trenches 14-22. Thus, the hybrid region 1-22 may be controlled based on both the first control trenches 14-21 (which receive the first control signal 13-21) and the second control trenches 14-22 (which receive the second control signal 13-22). In contrast, as explained above, in an embodiment, the RC IGBT region 1-22 does not include any first control trenches 14-21, and only the IGBT region 1-21 does not include any second control trenches 14-22.

[0085] In an embodiment, the trench-mesa pattern may further include a source trench 16 electrically connected to the first load terminal 11 and arranged at least in the IGBT-only region 1-21, the hybrid region 1-24 and optionally also in the diode-only region 1-23 (if the diode-only region 1-23 is implemented). For example, the RC IGBT region 1-22 does not include any source trench 16.

[0086] For example, the diode-only region 1-23 includes only the source trench 16, but not the control trench. In the RC IGBT region 1-22, there may be only the second control trench 14-22, but no source trench 16 and no first trench 14-21. In the hybrid region 1-24, two source trenches 16 may be arranged, for example, between respective two adjacent control trenches 14-21 / 14-22. For example, the first and second control trenches 14-21 / 14-22 may be arranged in an alternating manner along the first lateral direction X, and between each pair of control trenches 14-21 / 14-22, one or more source trenches 16 may be arranged. In the IGBT-only region 1-21, one, two or more source trenches 16 may be arranged, for example, between respective two adjacent first control trenches 14-21.

[0087] In an embodiment, the trench-mesa pattern further includes a first type mesa 17, which is arranged in each of the IGBT-only region 1-21, the RC IGBT region 1-22, and the mixed region 1-24. Each first type mesa 17 includes a source region 101 of a first conductivity type and a body region 102 of a second conductivity type. For clear representation, only a few source regions 101 present in the RC IGBT region 1-22 are provided with corresponding reference numerals. Each bold small square represents a source region 101. In addition, each illustrated trench in the RC IGBT region 1-22 represents a second control trench 14-22, wherein the second control trench 14-22 laterally confines the first type mesa 17 in the RC IGBT region 1-22.

[0088] With respect to each of the RC IGBT region 1-22, the hybrid region 1-24 and the IGBT-only region 1-21, in each first type mesa 17, both the source region 101 and the body region 102 are electrically connected to the first load terminal 11. At least the body region 102 isolates the source region 101 from the drift region 100.

[0089] In the IGBT-only region 1-21, each first type mesa 17 is arranged adjacent to at least one of the first control trenches 14-21. There, each first control trench 14-21 is configured to induce a conductive channel in the adjacent first type mesa 17 for conduction of a forward load current in response to receiving a corresponding configuration of the first control signal 13-21. Such conductive channel induction is generally known to the skilled person and is therefore not explained in more detail here.

[0090] In the RC IGBT region 1-22, each first type mesa 17 is arranged adjacent to at least one of the second control trenches 14-22. There, each second control trench 14-22 is configured to induce a conductive channel in the adjacent first type mesa 17 for conduction of a forward load current in response to receiving a corresponding configuration of the second control signal 13-22. As indicated above, such conductive channel induction is generally known to the skilled person and is therefore not explained in more detail here.

[0091] In the mixing region 1-24, each first type mesa 17 is arranged adjacent to at least one first control trench 14-21 of the first control trenches 14-21 or adjacent to at least one second control trench 14-22 of the second control trenches 14-22. Here, it is noted that the number of second control trenches 14-22 present in the mixing region 1-21 can be in the range of 20% to 60% of the number of first control trenches 14-21 present in the mixing region 1-21. For example, in the mixing region 1-24, the first control trenches 14-21 and the second control trenches 14-22 are arranged in an alternating manner with respect to the first lateral direction X. For example, between each pair of control trenches 14-21 / 14-22, a number (zero, one or more than one) of source trenches 16 are arranged.

[0092] For example, at least in the IGBT-only region 1-21 and optionally in the hybrid region 1-24, the trench-mesa pattern may further include second type mesas 18 which are not provided with source regions 101 and may or may not be electrically connected to the first load terminal 11. Furthermore, further trench types, such as floating trenches (whose trench electrodes are not electrically connected to a defined potential) or further control trenches may be provided.

[0093] For example, in the optionally provided diode-only region 1-23, only source trenches 16 are provided, but no control trenches are provided. These source trenches 16 can laterally delimit a diode mesa 19 in the diode-only region 1-23, where the body region 102 is electrically connected to the first load terminal 11. The diode mesa 19 is laterally delimited by the source trenches 16.

[0094] Figure 3 The trench-mesa pattern illustrated in FIG. 1 is an example. In another embodiment, a trench-mesa pattern different from this may be provided.

[0095] Here, it should be understood that according to the separation of the active region 1-2 into the hybrid region 1-24, the RC IGBT region 1-22, the IGBT-only region 1-21 and the optional diode-only region 1-23, the configuration of the front side 110 and the back side 120 (i.e., the trench-mesa pattern on the front side 110 and the back side emitter 108 on the back side 120) can be aligned with each other.

[0096] That is, in the embodiment,

[0097] - the trench-mesa configuration in the IGBT-only region 1 - 21 explained above laterally overlaps with the configuration of the first section 108 - 21 of the backside emitter 108 in the IGBT-only region 1 - 21 explained above;

[0098] - the trench-mesa configuration in the RC IGBT region 1 - 22 explained above laterally overlaps with the configuration of the second section 108 - 22 of the backside emitter 108 in the RC IGBT region 1 - 22 explained above;

[0099] the trench-mesa configuration in the diode-only region 1 - 23 explained above laterally overlaps with the configuration of the third section 108 - 23 of the backside emitter 108 in the diode-only region 1 - 23 explained above; and

[0100] The trench-mesa configuration in the mixing zone 1 - 24 explained above laterally overlaps with the configuration of the fourth section 108 - 24 of the backside emitter 108 in the mixing zone 1 - 24 explained above.

[0101] According to another embodiment, during the desaturation phase of the RC IGBT 1, if the first control signal 13-21 is set to a value corresponding to the off state, the RC IGBT 1 exhibits a first saturation voltage between the first load terminal 11 and the second load terminal 12, and if the second control signal 13-22 is set to a value corresponding to the off state, the RC IGBT 1 exhibits a second saturation voltage between the first load terminal 11 and the second load terminal 12, wherein the second saturation voltage is lower than the first saturation voltage.

[0102] In addition, for example, in combination with the embodiments described in the previous paragraph, the RC IGBT 1 may be provided with one or more of the following features:

[0103] I. In the mixed region 1-24, the density of the first control trenches 14-21 may be greater than the density of the second control trenches 14-22. Thus, a greater reduction in carrier concentration may be achieved based on providing an off potential for the first control signal 13-21 during the desaturation phase.

[0104] II. In the mixing region 1-22, only one of the first type mesas 17 is arranged adjacent to the corresponding second control groove 14-22, while each first control groove 14-21 may have two of the first type mesas 17 on both sides in the lateral direction (see Figure 6 ). Thus, the reduction in carrier concentration based on providing the second control signal 13-22 with an off potential is smaller than that based on providing the first control signal 13-21 with an off potential.

[0105] III. The distance dsat between (i) the conductive channel adjacent to the second control trench 14-22 and (ii) the first control trench 14-21 present during the desaturation phase (see Figure 7) is smaller than the distance dcon between (i) the conduction channel adjacent to the first control trench 14-21 and (ii) the second control trench 14-22 during the conduction phase. This feature can be satisfied even if one or more other trenches are arranged.

[0106] IV. The channel width of the conductive channel adjacent to the second control trench 14-22 is less than the channel width of the conductive channel adjacent to the first control trench 14-21, and / or the channel width per area ratio (e.g., expressed as μm / mm) associated with the conductive channel adjacent to the second control trench 14-22 is less than the channel width of the conductive channel adjacent to the first control trench 14-21. 2 ) is less than the channel width per area ratio (e.g., expressed as μm / mm) associated with the conductive channel adjacent to the first control trench 14-21. 2 ). Such a configuration, which may be provided, for example, in the mixing regions 1-24, may lead to an improved charge carrier density for the conduction phase.

[0107] V. The channel width of the conductive channel adjacent to the second control trench 14-22 in the hybrid region 1-24 is less than the channel width of the conductive channel adjacent to the second control trench 14-22 in the RCIGBT region 1-22, and / or the channel width per area ratio (e.g., expressed as μm / mm) associated with the conductive channel adjacent to the second control trench 14-22 in the hybrid region 1-24 is less than the channel width of the conductive channel adjacent to the second control trench 14-22 in the RCIGBT region 1-22. 2 ) is less than a channel width per area ratio (e.g., expressed as μm / mm) associated with a conductive channel adjacent to the second control trench 14-22 in the RC IGBT region 1-22. 2 ). This configuration may allow the load current scenario between the hybrid region 1-24 and the RC IGBT region 1-22 to be uniform at least in a certain range of load currents during the desaturation phase. In addition, within a single chip, the channel widths of the conductive channels adjacent to the second control trenches 14-22 may be different from each other.

[0108] In an embodiment, the RC IGBT 1 further includes a barrier region 105 of the first conductivity type, which couples the trench-mesa pattern in only the IGBT region 1-21 and the mixed region 1-24 to the drift region 100. For example, the dopant concentration of the barrier region 105 is greater than the dopant concentration of the drift region 100. According to the potential that can be represented by the second control signal 13-22, the dopant concentration of the barrier region 105 or the corresponding dopant dose can be adjusted to target Figure 4 Explain this in more detail.

[0109] like Figure 3 As shown in FIG. 1 , for example, the barrier region 105 is provided only in the IGBT-only region 1-21 and the mixed region 1-24, and is provided neither in the RC IGBT region 1-22 nor in the diode-only region 1-23.

[0110] Based on the above exemplary design, only the IGBT region 1-21 may constitute a low saturation IGBT controlled based on the first control signal 13-21 (Gate 1), and the RC IGBT region 1-22 may constitute an RCDC IGBT region having reverse conduction (RC) and diode control (DC) characteristics controlled based on the second control signal 13-22 (Gate 2). The hybrid region 1-24 may constitute a combination of a low saturation IGBT and an RCDC IGBT, and can therefore be controlled based on both the first control signal 13-21 (Gate 1) and the second control signal 13-22 (Gate 2).

[0111] In an embodiment, the RC IGBT region 1-22 occupies a total of 10% to 30% of the active region 1-2, the IGBT-only region 1-21 occupies a total of 40% to 60% of the active region 1-2, the hybrid region 1-24 occupies a total of 5% to 20% of the active region 1-2, and the diode-only region 1-23 occupies a total of 0% to 15% of the active region 1-2. Additionally or alternatively, the RC IGBT region 1-22 occupies a volume that is equal to at least 10% of the volume occupied by the IGBT-only region 1-21, and the hybrid region 1-24 occupies a volume that is equal to at least 5% of the volume occupied by the IGBT-only region 1-21.

[0112] Figure 6 A more detailed example of a segment of an RC IGBT region 1-22 is shown. Thus, two second type mesas 18 are arranged adjacent to the source trench 16. The source trench 16 includes a source trench electrode 161 electrically connected to the first load terminal 11. The source trench electrode 161 is isolated from the semiconductor body 10 based on the source trench insulator 162. The second control trench 14-22 is arranged between one of the second type mesas 18 and one of the first type mesas 17. The second control trench 14-22 includes a second control trench electrode 141-22 configured to receive a second control signal 13-22 (Gate 2). The second control trench electrode 141-22 is isolated from the semiconductor body 10 based on the second control trench insulator 142-22. In the IGBT region 1-21 only, the arrangement is similar, except that instead of the second control trench 14-22, a first control trench is arranged.

[0113] Figure 7A more detailed example of a segment of a hybrid region 1-24 is illustrated. In addition, there, two second type mesas 18 or one of the second type mesas and one of the first type mesas 17 can be arranged adjacent to each source trench 16. The second control trench 14-22 is arranged between one of the second type mesas 18 and one of the first type mesas 17. The first control trench 14-21 is arranged between two first type mesas 17 in the first type mesas 17. Like the second control trench 14-22, the first control trench 14-21 includes a first control trench electrode 141-21 configured to receive a first control signal 13-21 (Gate 1). Based on the first control trench insulator 142-21, the first control trench electrode 141-21 is isolated from the semiconductor body 10. However, according to an embodiment, each conductive channel formed below the corresponding source region 101 is controlled by the first control trench electrode 141-21 or the second control trench electrode 141-22.

[0114] Due to their differences in configuration, the hybrid region 1-24 exhibits theoretical independent output characteristics that are different from those of the RC IGBT region 1-22. This aspect is exemplarily illustrated in Figure 5 There, the horizontal axis indicates the voltage V across the first load terminal 11 and the second load terminal 12 CE The vertical axis indicates the forward load current I C Both the first control signal 13-21 (Gate 1) and the second control signal 13-22 (Gate 2) exhibit a configuration corresponding to the on-state of the RC IGBT 1. In the mixed region 1-24, the forward load current I C is limited to less than the maximum value I max value, and the RC IGBT regions 1-22 are configured to conduct greater than the maximum value I max The forward load current I C For example, from Figure 3 It is clearly seen that the RC IGBT region 1-22 may exhibit a conductive channel width ratio per area that is (e.g., significantly) greater than that in the hybrid region 1-24 (see the high density of source regions 101 in the RC IGBT region 1-22 compared to the hybrid region 1-24). The term theoretical independent output characteristic describes the output curve of a respective region without interfering with other regions.

[0115] A method of operating an RC IGBT 1 according to one of the previous embodiments is also presented herein. The method comprises: controlling the RC IGBT 1 based on a first control signal 13 - 21 (Gate 1 ) and a second control signal 13 - 22 (Gate 2 ).

[0116] An exemplary method is illustrated in Figure 4 Now we will refer to Figure 4 There, the first control signal 13-21 is illustrated as having a voltage V G1 (ie, the voltage of the first control signal 13-21 (Gate 1)), and the second control signal 13-22 is illustrated as having a voltage indicated as V G2 (i.e., the voltage of the second control signal 13-22 (Gate 2)). Figure 4 According to the two variants (A) and (B) illustrated in the figure (that is, providing two possible voltage levels or providing three possible voltage levels for the second control signal 13-22), two possibilities are explained. As usual, the first control signal 13-21 can be generated by providing a voltage between the first load terminal 11 and the first control groove electrode 141-21, and the second control signal 13-22 can be generated by providing a voltage between the first load terminal 11 and the second control groove electrode 141-22. According to a third possibility, which is not illustrated, the route of the first control signal 13-21 is the same as the route illustrated in the variants (A) and (B), and with respect to timing, the route of the second control signal 13-22 corresponds to the route illustrated in the variants (A) and (B), but the second control signal 13-22 exhibits the same off potential as the first control signal 13-21, for example, -15V instead of 0V or -8V. That is, for the third possibility, the on potential and the off potential are the same for the two control signals 13-21 and 13-22.

[0117] With regard to the operation of the RC IGBT 1, in an embodiment, it can be ensured that, due to the second control signal 13-22 being at the off potential, the carrier concentration in the mixed region 1-24 during the conduction phase does not decrease or at most decreases slightly. At the same time, it can be ensured that, based on the first control signal 13-21 being at the off potential, the carrier concentration in the mixed region 1-24 should decrease significantly during the desaturation phase.

[0118] In the example, the situation is thus provided that at least during the desaturation phase of the forward conduction state of the RC IGBT 1, the off potential of the second control signal 13-22 is different from the off potential of the first control signal 13-21, for example greater than the off potential of the first control signal 13-21, such as Figure 4 For example, instead of -15V, the off potential of the second control signal 13-22 may be at -8V or 0V.

[0119] Furthermore, during the conduction phase, the off potential of the second control signal 13 - 22 can be at 0V or at −15V, whereas the off potential of the first control signal 13 - 21 is at −15V.

[0120] In the case of a negative off potential, the following may be beneficial: providing the barrier region 105 with, for example, more than 2*10 13 cm -2 A relatively high dopant dose, for example, 5*10 13 cm -2 In the case of such a barrier region 105, for the off potential of the second control signal 13-22 in the range of 0V to -8V, the saturation voltage V CE,sat Only a slight increase occurs, which therefore produces a low reduction in the carrier concentration, whereas for an off potential of -15 V of the first control signal 13 - 21 a large desaturation effect is observed.

[0121] Typically, during the conduction phase of the RC IGBT 1, whether the RC IGBT 1 is conducting a forward load current or a reverse load current, the potential of the first control signal 13-21 may be as high as a first threshold value (e.g., at +15V), while the potential of the second control signal 13-22 is lower than the first threshold value (e.g., at 0V or -8V), see Figure 4 Two variants (A) and (B).

[0122] In addition, during the desaturation phase of the RC IGBT 1, whether the RC IGBT 1 conducts a forward load current or a reverse load current, the potential of the first control signal 13-21 may be as low as a second threshold value (e.g., at -15V), while the potential of the second control signal 13-22 is greater than the second threshold value (e.g., at +15V), see Figure 4 Two variants (A) and (B).

[0123] In the above, embodiments and corresponding operation methods of RC IGBTs are explained. For example, these RC IGBTs are based on silicon (Si). Therefore, a single crystal semiconductor region or layer (e.g., a semiconductor body and its regions / zones, such as regions, etc.) can be a single crystal Si region or Si layer. In other embodiments, polycrystalline or amorphous silicon may be used.

[0124] However, it should be understood that the semiconductor body and its regions / zones can be made of any semiconductor material suitable for manufacturing semiconductor devices. Examples of such materials include, but are not limited to: elemental 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) (to name a few examples). The aforementioned semiconductor materials are also referred to as "homojunction 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), silicon-silicon carbide (SixC1-x) and silicon-SiGe heterojunction semiconductor materials. For power semiconductor switch applications, Si, SiC, GaAs and GaN materials are currently used.

[0125] Spatially relative terms such as "under," "beneath," "lower," "over," "upper," etc. are used for ease of description to explain the positioning of one element relative to a second element. These terms are intended to encompass different orientations of the respective devices in addition to those depicted in the accompanying drawings. Additionally, terms such as "first," "second," etc. are also used to describe various elements, regions, sections, etc., and are also not intended to be limiting. Similar terms may refer to similar elements throughout the description.

[0126] As used herein, the terms “having,” “containing,” “including,” “comprising,” “exhibiting,” and the like are open-ended terms that indicate the presence of stated elements or features, but do not preclude additional elements or features.

[0127] With the above range of variations and applications in mind, it should be understood that the present invention is not limited by the foregoing description, nor by the accompanying drawings. Instead, the present invention is limited only by the following claims and their legal equivalents.

Claims

1. A RCIGBT (1) comprising an active region (1-2) in a single chip, the active region (1-2) being configured to conduct both a forward load current and a reverse load current between a first load terminal (11) at a front side (110) of a semiconductor body (10) of the RCIGBT (1) and a second load terminal (12) at a rear side (120) of the semiconductor body (10), wherein the active region (1-2) is separated into at least: - only IGBT regions (1-21), at least 90% of which are configured to conduct only the forward load current based on the first control signal (13-21); -RC IGBT regions (1-22), at least 90% of which are configured to conduct o the reverse load current, and o Based on the second control signal (13-22), conducting the forward load current; - a mixing zone (1-24), at least 90% of which are configured to conduct the forward load current based on both the first control signal (13-21) and the second control signal (13-22).

2. The RCIGBT (1) of claim 1, wherein the second control signal (13-22) is different from the first control signal (13-21).

3. The RCIGBT (1) according to claim 1 or 2, wherein the IGBT-only region (1-21), the RCIGBT region (1-22) and the mixed region (1-24) are equal to at least 80% of the active region (1-2).

4. The RCIGBT (1) according to one or more of the preceding claims, wherein the IGBT-only region (1-21), the RCIGBT region (1-22) and the mixed region (1-24) are spatially separated from each other, and optionally, wherein: - the IGBT-only region (1-21) is a first continuous region; and / or - the RCIGBT region (1-22) is a second continuous region; and / or - the mixing zone (1-24) is a third continuous zone; and / or - one or more of the IGBT-only region (1-21), the RC IGBT region (1-22) and the mixed region (1-24) each exhibits a total lateral extension of at least 60% of the vertical thickness (d) of the semiconductor body (10).

5. The RCIGBT (1) as claimed in one or more of the preceding claims, further comprising: - diode-only regions (1-23), at least 90% of which are configured to conduct only said reverse load current, wherein, optionally, o no control trench (14-21; 14-22) is present in said diode-only region (1-23); and / or o No source region (101) is present in the diode-only region (1-23).

6. The RCIGBT (1) as claimed in one or more of the preceding claims, further comprising: A drift region (100) of a first conductivity type is located in the semiconductor body (10), wherein the drift region (100) is shared by each of the IGBT-only region (1-21), the RCIGBT region (1-22), the hybrid region (1-24) and the diode-only region (1-23) if the diode-only region (1-23) is implemented.

7. The RCIGBT (1) according to claim 6, further comprising: A backside emitter (108), coupled to the drift region (100), is in electrical connection with the second load terminal (12), wherein the backside emitter (108) is configured according to the active region (1-2) being separated into at least the IGBT-only region (1-21), the RC IGBT region (1-22) and the mixed region (1-24) and the diode-only region (1-23) if the diode-only region (1-23) is implemented.

8. The RC IGBT (1) according to claim 7, wherein the rear-side emitter (108) is configured with: - a first segment (108-21) of a second conductivity type located in a portion of the active region (1-2) where the IGBT-only region (1-21) exists; and - a second section (108-22), located in the portion of the active area (1-2) where the RCIGBT area (1-22) exists, comprising both a first sub-section (108-221) of the first conductivity type and a second sub-section (108-222) of the second conductivity type; and - a fourth section (108-24) located in a portion of the active region (1-2) where the mixed region (1-24) exists, wherein the fourth section (108-24) is configured in terms of conductivity type according to at least one of the first section (108-21) and the second section (108-22); - and optionally, if said diode-only zone (1-23) is implemented, then configured with - a third section (108-23) of the first conductivity type, located in the portion of the active region (1-2) where the diode-only region (1-23) exists.

9. The RC IGBT (1) of claim 8, wherein the first section (108-21) of the back-side emitter (108) - for its total lateral extension along the first lateral direction (X) and at a certain vertical level, exhibits at least 2*10 15 cm -3 The average adulteration concentration of - shifting at least the mixing region (1-24) relative to the RCIGBT region (1-22); and / or - exhibiting a variation of the concentration of said dopant at a certain vertical level and along at least one of said first lateral direction (X) and said second lateral direction (Y).

10. The RCIGBT (1) of claim 5 and claim 8 or 9, wherein each of the first sub-segments (108-221) of the second segment (108-22) of the back-side emitter (108) exhibits, for its respective total lateral extension along the first lateral direction (X) and at a certain vertical level, at least 1*10 18 cm -3 and optionally wherein each of the second sub-segments (108-222) is shifted relative to the diode-only region (1-23) by a second distance (d2) of at least 20% of the thickness (d) of the semiconductor body (10).

11. The RC IGBT (1) as claimed in one or more of the preceding claims 7 to 10, further comprising: The field stop zone (107) of the first conductivity type is arranged to contact both the drift zone (100) and the first segment (108-21), the second segment (108-22), the fourth segment (108-24) and each of the third segment (108-23) if the third segment (108-23) is implemented, wherein the dopant concentration of the field stop zone (107) is greater than the dopant concentration of the drift zone (100).

12. The RC IGBT (1) as claimed in one or more of the preceding claims 6 to 11, further comprising: A trench-mesa pattern is provided on the front side (110), wherein the trench-mesa pattern is configured according to the active area (1-2) being separated into at least the IGBT-only area (1-21), the RC IGBT area (1-22) and the mixed area (1-24) and the diode-only area (1-23) if the diode-only area (1-23) is implemented.

13. The RC IGBT (1) of claim 12, wherein the trench-mesa pattern comprises a first control trench (14-21) configured to receive the first control signal (13-21) and a second control trench (14-22) configured to receive the second control signal (13-22), and wherein: - the IGBT-only region (1-21) comprises a plurality of first control trenches (14-21), but optionally does not comprise any of the second control trenches (14-22); and - the RCIGBT region (1-22) comprises a plurality of second control trenches (14-22), but optionally does not comprise any of the first control trenches (14-21); and The mixing zone (1-24) comprises both a plurality of first control grooves (14-21) and a plurality of second control grooves (14-22).

14. The RCIGBT (1) according to claim 12 or 13, wherein the trench-mesa pattern further comprises: - a source trench (16) electrically connected to the first load terminal (11) and arranged at least in the IGBT-only region (1-21) and the hybrid region (1-24) and optionally also in the diode-only region (1-23) if the diode-only region (1-23) is implemented.

15. The RCIGBT (1) according to one or more of the preceding claims 12 to 14, wherein the trench-mesa pattern further comprises: - a first type mesa (17) arranged in each of the IGBT-only region (1-21), the RC IGBT region (1-23) and the mixed region (1-24), wherein each first type mesa (17) comprises a source region (101) of the first conductivity type and a body region (102) of the second conductivity type, wherein both the source region (101) and the body region (102) are electrically connected to the first load terminal (11), and wherein at least the body region (102) isolates the source region (101) from the drift region (100).

16. The RCIGBT (1) as claimed in claims 13 and 15, wherein - in the IGBT-only region (1-21), each first type mesa (17) is arranged adjacent to at least one of the first control trenches (14-21), and wherein each first control trench (14-21) is configured to induce a conductive channel in an adjacent first type mesa (17) for conduction of the forward load current in response to receiving a corresponding configuration of the first control signal (13-21); and - in the RCIGBT region (1-22), each first type mesa (17) is arranged adjacent to at least one of the second control trenches (14-22), and wherein each second control trench (14-22) is configured to induce a conductive channel in an adjacent first type mesa (17) for conduction of the forward load current in response to receiving a corresponding configuration of the second control signal (13-22); and - In the mixing zone (1-24), each first type mesa (17) is arranged adjacent to at least one first control groove (14-21) of the first control grooves (14-21) or adjacent to at least one second control groove (14-22) of the second control grooves (14-22).

17. The RCIGBT (1) of claim 16, wherein in the hybrid region (1-24), with respect to a first lateral direction (X), the first control trenches (14-21) and the second control trenches (14-22) are arranged in an alternating manner.

18. The RCIGBT (1) as claimed in one or more of the preceding claims 12 to 17, further comprising: The barrier region (105) of the first conductivity type couples the trench-mesa pattern in the IGBT-only region (1-21) and the mixed region (1-24) to the drift region (100), wherein the dopant concentration of the barrier region (105) is greater than the dopant concentration of the drift region (100).

19. The RCIGBT (1) as claimed in one or more of the preceding claims, wherein during a desaturation phase of the RCIGBT (1), - if the first control signal (13-21) is set to a value corresponding to an off state, the RC IGBT (1) exhibits a first saturation voltage between the first load terminal (11) and the second load terminal (12), and - if the second control signal (13-22) is set to a value corresponding to an off state, the RC IGBT (1) exhibits a second saturation voltage between the first load terminal (11) and the second load terminal (12), wherein the second saturation voltage is lower than the first saturation voltage.

20. The RC IGBT (1) according to one or more of the preceding claims, wherein said RC IGBT region (1-22) exhibits a conducting channel width ratio per area which is greater than a conducting channel width ratio per area in said mixed region (1-24).

21. A method of operating a RCIGBT (1) as claimed in any one of the preceding claims, the method comprising: - controlling the RCIGBT (1) based on the first control signal (13-21) and the second control signal (13-22); in - Optionally, during a desaturation phase of the forward conduction state of the RCIGBT (1), the off potential of the second control signal (13-22) is different from the off potential of the first control signal (13-21), for example, greater than the off potential of the first control signal (13-21).

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