Power semiconductor devices including thyristors and bipolar junction transistors

Abstract

A power semiconductor device (100) is provided, including a thyristor structure (50) and a bipolar junction transistor (60) integrated on the same semiconductor wafer (110). The thyristor structure (50) includes a gate electrode (161), a first main electrode (162) disposed on a first main side (111) of the semiconductor wafer (110), and a second main electrode (163) disposed on a second main side (112) of the semiconductor wafer (110). The bipolar junction transistor (60) includes a base electrode (171) electrically separated from the gate electrode (161), a third main electrode (172) disposed on the first main side (111), and a fourth main electrode (173) disposed on the second main side (112). The base electrode (171) corresponds to the base terminal of the bipolar junction transistor (60). The third main electrode (172) corresponds to one of the collector terminal and the emitter terminal of the bipolar junction transistor (60), and the fourth main electrode (173) corresponds to the other of the collector terminal and the emitter terminal of the bipolar junction transistor (60). The first main electrode (162) is electrically connected to the third main electrode (172), and the second main electrode (163) is electrically connected to the fourth main electrode (173).

Description

Technical Field

[0001] This invention relates to a power semiconductor device, and more particularly to a power semiconductor device comprising a thyristor structure and a bipolar junction transistor. Background Technology

[0002] In the field of power semiconductor devices, there are known power turn-off semiconductor devices, such as gate turn-off thyristors (GTOs) and gate-commutated thyristors (GCTs), especially integrated gate-commutated thyristors (IGCTs). In reverse-conducting (RC) IGCTs, the freewheeling diode can be integrated into the device wafer.

[0003] US 5304823 A discloses a semiconductor integrated circuit that can have a high holding current without being adversely affected by a high gate current. This circuit includes a PNPN device and a junction bipolar transistor (JBT), wherein another doped region, having the same conductivity type as the collector region of the transistor but more heavily doped than the collector region, prevents the devices from interfering with each other. The JBT has a current gain of at least 10, and the base-collector and base-emitter junctions have a reverse breakdown voltage of at least 50 volts. A PN diode can also be used in this circuit.

[0004] US 5442219 A discloses a semiconductor device comprising a half-bridge circuit, wherein one of the two arms or elements of the half-bridge circuit is a thyristor and the other is a bipolar transistor. It is vertically configured as a single semiconductor chip, with the primary conductor-type cathode region of the thyristor and the primary conductor-type collector region of the bipolar transistor sharing a common region. A first isolation region is formed between the intermediate layer of the thyristor and the aforementioned common region. A second isolation region is formed in the first isolation region disposed between the intermediate layer of the thyristor and the base region of the bipolar transistor. Because the upper and lower arms of the half-bridge are vertically configured, the circuit provides excellent area efficiency, current amplification factor, and current capacity. No specific isolation layer is required to isolate the upper and lower arms. The first and second isolation regions suppress leakage current due to the formation of the associated npn and pnp structures.

[0005] A reverse-conducting power semiconductor device having a wafer is known from US 20130207157 A1, wherein the wafer has a first main side and a second main side parallel to the first main side. The device includes a plurality of diode cells and a plurality of IGCT cells, each IGCT cell including, between the first and second main sides: a first anode electrode, a first anode layer of a first conductivity type on the first anode electrode, a buffer layer of a second conductivity type on the first anode layer, a drift layer of a second conductivity type on the buffer layer, a base layer of a first conductivity type on the drift layer, a first cathode layer of a second conductivity type on the base layer, and a cathode electrode on the first cathode layer. A hybrid portion includes a second anode layer of the diode cells alternating with the first cathode layer of the IGCT cells.

[0006] A semiconductor device is known from EP 0110777 A1, comprising a first emitter region, a first suppressor base region adjacent to the first emitter region, a second main base region, and a second emitter region. The first emitter region is divided into several main regions electrically connected together by cathode contacts. The first base region is divided into several regions electrically connected together by suppressor gate contacts. The latter contacts are connected to the cathode contacts via a switch, enabling a short circuit to be generated between the suppressor gate and the cathode to suppress the thyristor's self-ignition capability. The thickness and doping of the base and emitter regions are selected such that the thyristor self-ignites solely through capacitive current at normal ambient temperature when the AC power supply voltage drops to zero.

[0007] As an example of a known power-off semiconductor device Figure 1A and Figure 1B The prior art RC-IGCT1 is shown in the figure. For example, such an RC-IGCT is described in WO 2012 / 041958 A2. Figure 1A A portion of the known RC-IGCT1 is shown in the cross-sectional view. Figure 1B The layout of the device is shown in the top view. The RC-IGCT 1 includes multiple thyristor units 2 and integrated freewheeling diodes 3. All thyristor units 2 and integrated freewheeling diodes 2 are formed in a single wafer 10, which has a first main side 11 and a second main side 12. The first main side is the cathode side of the RC-IGCT 1, and the second main side is the anode side of the RC-IGCT 1.

[0008] like Figure 1A As shown, each thyristor unit 2 includes a first cathode electrode 21 and an inductor 22 from the first main side 11 to the second main side 12 of the wafer 10. + Doped cathode semiconductor layer 22, p-doped base semiconductor layer 23, n -The system includes a doped drift semiconductor layer 24, an n-doped buffer semiconductor layer 25, a p+ doped first anode semiconductor layer 26, and a first anode electrode 27. The cathode semiconductor layer portions 22 of the plurality of thyristor units 2 form the first cathode semiconductor layer. The buffer semiconductor layer 25 has a doping concentration that rises toward the second main side 12, while the drift semiconductor layer 24 typically has a constant doping concentration.

[0009] Furthermore, each thyristor unit 2 has a gate electrode 20, which is laterally arranged on the first main side 11 of the wafer 10 relative to the cathode semiconductor layer portion 22 and in contact with the base semiconductor layer 23, but separated from the first cathode electrode 21 and the cathode semiconductor layer portion 22. Here, the term "lateral" refers to the position in the lateral direction, which is the direction parallel to the first main side 11.

[0010] In the circumferential edge region of the wafer 10, an integrated single freewheeling diode 3 is arranged, which extends along... Figure 1B The cross-sectional view of line AA' in the diagram can also be found in Figure 1A As seen in the image, the freewheeling diode 3, extending from the first main side 11 to the second main side 12 of the wafer 10, includes a second anode electrode 31, a p-doped second anode semiconductor layer 32, and an n-doped... + The doped second cathode semiconductor layer 33 and the second cathode electrode 34, wherein the second cathode semiconductor layer 33 is through n - The doped drift semiconductor layer 24 is separated from the p-doped second anode semiconductor layer 32.

[0011] The arrangement of multiple thyristor units 2 in RC-IGCT 1 is as follows: Figure 1B The diagram shows a top view of the first main side 11 of the wafer. The cathode semiconductor layer portion 22 of the RC-IGCT 1 is formed in a strip shape, aligned longitudinally and radially, wherein the radial direction extends from the center of the side of the circular wafer 10 and is parallel to the first main side 11 of the wafer 10. Furthermore, the strip shape should be understood as layers that have a longer extension in one direction (their longitudinal direction) than in other directions (by having longer sides) and are generally arranged parallel to each other. Multiple strip-shaped cathode semiconductor layer portions 22 are arranged in concentric rings around the center of the device. A common gate contact 40 is arranged in the central region of the wafer 10, and all the gate electrodes 20 of the multiple thyristor units 2 are electrically connected to this common gate contact 40. The gate electrodes 20 of the thyristor units 2, the common gate contact 40, and the connections between them are implemented as a gate metallization layer surrounding all the cathode semiconductor layer portions 22.

[0012] To turn off the RC-IGCT, a short control gate current pulse is applied to the gate electrode 20 of the plurality of thyristor units 2 through the common gate contact 40.

[0013] IGCTs being locked into the on state means they do not actively control the anode voltage during conduction. While this is advantageous in terms of their own losses, it is problematic for freewheeling diodes. With both high reverse voltage and reverse current in a freewheeling diode, its losses during reverse recovery are relatively high. To protect the accompanying diode, a dI / dt limiting inductor, i.e., a choke, is always included in existing IGCT circuits. The choke leads to overvoltage problems, requiring another protective circuit (overvoltage clamp) when using IGCTs. The clamping circuit consists of a clamping capacitor, a diode, and a resistor.

[0014] The procurement and assembly costs of all protective circuit components are high. This additional cost disadvantage, along with the relatively high diode losses during IGCT conduction, limits the inherent loss advantage of IGCTs over insulated-gate bipolar transistors (IGBTs). Summary of the Invention

[0015] In view of the above, an object of the present invention is to provide a power semiconductor device comprising a thyristor structure that avoids the aforementioned disadvantages of IGCT. Exemplarily, an object of the present invention is to provide a power semiconductor device that has reduced system losses and less need for protective circuitry.

[0016] The object of this invention is achieved by a power semiconductor device as described below. Further developments of the invention are specified below.

[0017] The power semiconductor device of the present invention includes: a semiconductor wafer having a first main side and a second main side opposite to the first main side; a thyristor structure; and a bipolar junction transistor arranged laterally relative to the thyristor structure. The thyristor structure comprises, in order from the first main side to the second main side: • First emitter layer of the first conductivity type; • A first base layer of a second conductivity type, different from the first conductivity type, wherein the first emitter layer is in direct contact with the first base layer to form a first pn junction between the first base layer and the first emitter layer; • A second base layer of a first conductivity type, wherein the first base layer and the second base layer are in direct contact to form a second pn junction between the first base layer and the second base layer; and • A second emitter layer of the second conductivity type, which is separated from the first base layer through a second base layer, wherein the second base layer and the second emitter layer are in direct contact to form a third pn junction between the second base layer and the second emitter layer. The thyristor structure also includes: • Gate electrode, which is arranged laterally relative to the first emitter layer and forms an ohmic contact with the first base layer; • A first main electrode, disposed on a first main side and forming an ohmic contact with the first emitter layer; and • The second main electrode is disposed on the second main side and forms an ohmic contact with the second emitter layer. A bipolar junction transistor (BJT) includes a base electrode electrically separated from the gate electrode, a third main electrode disposed on a first main side, and a fourth main electrode disposed on a second main side. The base electrode corresponds to the base terminal of the BJT. The third main electrode corresponds to one of the collector terminal and the emitter terminal of the BJT, and the fourth main electrode corresponds to the other of the collector terminal and the emitter terminal of the BJT. The first main electrode is electrically connected to the third main electrode, and the second main electrode is electrically connected to the fourth main electrode.

[0018] Throughout this specification, the lateral direction should be understood as a direction parallel to the second principal side. In the case of an uneven second principal side, the lateral direction parallel to the second principal side should be understood as a direction parallel to the reference plane, where the arithmetic mean of the distances between the second principal side and the reference plane is minimized (compared to all other planes), wherein the arithmetic mean is calculated from the distance values ​​of all points on the second principal side. Throughout this specification, the term "lateral" should refer to the lateral direction as defined herein. For example, if an element is described as being arranged laterally relative to another element, it is arranged at a position offset from the position of the other element in the lateral direction as defined above.

[0019] Bipolar junction transistors (BJTs) integrated into a semiconductor wafer allow for the control and modulation of the voltage between the third and fourth main electrodes by controlling the voltage applied to the base electrode. This allows the BJT to be turned on first and then the thyristor structure in a controlled manner, without the need for the commonly used protection circuitry (chokes and clamps) described in more detail below. By connecting the first main electrode to the third main electrode and the second main electrode to the fourth main electrode, the modulation of the voltage between the third and fourth main electrodes is efficiently coupled to the voltage between the first and second main electrodes, thereby allowing the modulation of the voltage between the first and second main electrodes via the control of the BJT.

[0020] In an exemplary embodiment, the semiconductor wafer includes a separation region of a first conductivity type, wherein the separation region is laterally disposed between a bipolar junction transistor (BJT) and a thyristor structure to isolate the BJT from the thyristor by at least the separation region. The separation region electrically decouples the BJT from the thyristor structure. This allows for independent control of the BJT and the thyristor structure.

[0021] In an exemplary embodiment, the semiconductor wafer includes a freewheeling diode arranged laterally relative to the thyristor structure and to the bipolar junction transistor. The freewheeling diode includes, in order from a first main side to a second main side, a first diode layer of a second conductivity type and a second diode layer of the first conductivity type forming a fourth pn junction with the first diode layer. Using the freewheeling diode, the power semiconductor device is an inverting (RC) power semiconductor device. The bipolar junction transistor allows for reduced losses during the reverse period of the freewheeling diode when the thyristor structure is on.

[0022] In an exemplary embodiment, the second base layer includes a relatively lightly doped thyristor drift layer portion and a thyristor buffer layer portion having a higher doping concentration than the thyristor drift layer portion, wherein the thyristor buffer layer portion separates the thyristor drift layer portion from the second emitter layer. The asymmetric design of the second base layer, including the thyristor drift layer portion and the thyristor buffer layer portion, allows for a reduction in the layer thickness of the second base layer, thereby significantly reducing the on-state loss in the thyristor structure.

[0023] In an exemplary embodiment, the thyristor structure includes a gate-commutated thyristor (GCT) device, which includes a plurality of thyristor units. In this exemplary embodiment, each thyristor unit may include: • Part of the first emitter layer; • A portion of the first base layer, wherein the portion of the first emitter layer is in direct contact with the portion of the first base layer to form a portion of the first pn junction between the first base layer and the first emitter layer; • A portion of the second base layer, wherein this portion of the first base layer is in direct contact with the second base layer to form a portion of the second pn junction between the first and second base layers; and A portion of the second emitter layer is separated from the portion of the first base layer by this portion of the second base layer, wherein this portion of the second base layer is in direct contact with the portion of the second emitter layer to form a portion of a third pn junction between the second base layer and the second emitter layer. In this exemplary embodiment, the thyristor structure may further include: • A portion of the gate electrode is arranged laterally relative to that portion of the first emitter layer (154) and forms an ohmic contact with that portion of the first base layer; • A portion of the first main electrode forms an ohmic contact with that portion (154a, 154b) of the first emitter layer (154); and • A portion of the second main electrode (163) forms an ohmic contact with that portion of the second emitter layer (158).

[0024] In this case, this portion of the first emitter layer (154) of each thyristor unit can be laterally separated from this portion of the first emitter layer of each other thyristor unit.

[0025] Integrated gate-commutated thyristors (IGCTs) can be implemented using multiple thyristor units, which in existing technologies require extensive protection circuitry due to their rapid turn-on. Compared to, for example, IGBTs, this extensive protection circuitry offsets the advantage of lower inherent losses. By utilizing integrated bipolar junction transistors, the need for protection circuitry can be eliminated, and the potential of IGCTs in terms of low inherent losses can be utilized more efficiently.

[0026] In an exemplary embodiment, the bipolar junction transistor includes, in order from the first main side to the second main side: • The third emitter layer of the first conductivity type; • A third base layer of the second conductivity type, which is connected to the third emitter layer through a first base-emitter pn junction; • The first conductivity type of transistor drift layer portion, which is connected to the third base layer via a drift layer-base pn junction; and • A collector layer of the first conductivity type has a higher doping concentration than the transistor drift layer portion and is in direct contact with the transistor drift layer portion or connected to the transistor drift layer portion through a transistor buffer layer portion of the first conductivity type.

[0027] The transistor buffer layer portion has a higher doping concentration than the transistor drift layer portion. For example, the transistor buffer layer portion may have a doping concentration that rises towards the second main side, while the transistor drift layer portion may have a constant doping concentration. The doping concentration of the buffer layer portion may be lower than that of the collector layer.

[0028] In this exemplary embodiment, the third main electrode forms an ohmic contact with the third emitter layer, the fourth main electrode forms an ohmic contact with the collector layer, and the base electrode is arranged laterally relative to the third emitter layer and forms an ohmic contact with the third base layer.

[0029] This particular configuration of a bipolar junction transistor allows the use of only the existing profile and places the gate and base electrodes on the same side of the device, i.e., on the first main side.

[0030] In this exemplary embodiment, the depth of the first base layer (i.e., the depth to which the first base layer extends from the first main side) can be the same as the depth of the third base layer (i.e., the depth to which the third base layer extends from the first main side). Furthermore, in this exemplary embodiment, the first base layer can have the same vertical doping concentration distribution at a first lateral position as the third base layer at a second lateral position, wherein at the first lateral position, the lateral gradient of the doping concentration of the first base layer is zero for all vertical positions, and at the second lateral position, the lateral gradient of the doping concentration of the third base layer is zero for all vertical positions. This similar depth and / or doping distribution allows the first and third base layers to be formed in the same fabrication steps, thereby facilitating the fabrication of power semiconductor devices.

[0031] In an exemplary embodiment, the ratio between the area of ​​the bipolar junction transistor and the area of ​​the thyristor is in the range of 0.1 to 0.3 or in the range of 0.15 to 0.25, wherein the thyristor area is defined as the area occupied by the first base layer of the thyristor structure in a horizontal projection on a plane parallel to the second main side, and wherein the area of ​​the bipolar junction transistor is defined as the area occupied by the third base layer in a horizontal projection on a plane parallel to the second main side.

[0032] This ratio between the area of ​​the bipolar junction transistor and the area of ​​the thyristor results in improved thermal management and optimal thermal performance of the power semiconductor device during both thyristor structure operation and bipolar junction transistor operation.

[0033] In an exemplary embodiment, the bipolar junction transistor includes: • A collector layer of the second conductivity type is arranged adjacent to the first main side; • A third base layer of the first conductivity type is arranged adjacent to the second main side; • A third emitter layer of the second conductivity type, arranged adjacent to the second main side and laterally relative to the third base layer; and • The transistor drift layer portion, which is arranged between each of the third base layer and the third emitter layer and the collector layer. In this configuration, the collector layer is connected to the transistor drift layer portion via a collector-drift layer pn junction. The third base layer is in direct contact with the transistor drift layer or connected to the transistor drift layer portion via a transistor buffer layer portion of a first conductivity type. The third base layer is connected to the third emitter layer via a second base-emitter pn junction. The third main electrode forms an ohmic contact with the collector layer, and the fourth main electrode forms an ohmic contact with the third emitter layer. The base electrode is arranged laterally relative to the fourth main electrode and forms an ohmic contact with the third base layer. The transistor buffer layer portion has a higher doping concentration than the transistor drift layer portion. For example, the transistor buffer layer portion may have a doping concentration that rises towards the second main side, while the transistor drift layer portion may have a constant doping concentration. The doping concentration of the transistor buffer layer portion may be lower than that of the collector layer.

[0034] In such an exemplary embodiment, the bipolar junction transistor has a very wide base, resulting in poor current amplification. This is advantageous because the goal is to mitigate voltage, which contributes to low current amplification.

[0035] The depth of the first base layer (extending from the first main side to that depth) can be the same as the depth of the collector layer (extending from the first main side to that depth). In this configuration, the first base layer and the collector layer can be fabricated simultaneously to facilitate the fabrication of power semiconductor devices.

[0036] The depth of the second emitter layer (extending from the second main side to this depth) can be the same as the depth of the third emitter layer (extending from the second main side to this depth). In this configuration, the second and third emitter layers can be fabricated simultaneously to facilitate the fabrication of power semiconductor devices.

[0037] In an exemplary embodiment, the power semiconductor device includes: a first control unit electrically connected to a gate electrode and configured to control a voltage or current applied to the gate electrode; and a second control unit electrically configured to control a current or voltage applied to a base electrode. The first and second control units are configured to first turn on the bipolar junction transistor (BJT) in a state where the thyristor structure is in a forward blocking state, then turn on the thyristor structure from the forward blocking state to a forward conducting state, and then turn off the BJT while maintaining the thyristor structure in the forward conducting state.

[0038] Individual control of the voltage or current applied to the gate and base electrodes facilitates the conduction of the thyristor structure without requiring additional protection circuitry. Attached Figure Description

[0039] Detailed embodiments of the present invention will now be described with reference to the accompanying drawings, in which: Figure 1A It is part of the known power-off semiconductor devices in the prior art. Figure 1B The cross section of line AA' in the middle; Figure 1B yes Figure 1A A top view of the power-off semiconductor device shown; Figure 2A A power semiconductor device according to the first embodiment is shown in a vertical cross-sectional view; Figure 2B A top view of a power semiconductor device according to a first embodiment is shown; Figure 2C A horizontal cross-sectional view of a power semiconductor device according to a first embodiment is shown; Figure 3A A power semiconductor device according to the second embodiment is shown in a vertical cross-sectional view; Figure 3B A top view of a power semiconductor device according to a second embodiment is shown; Figure 3C A horizontal cross-sectional view of a power semiconductor device according to a second embodiment is shown; Figure 4 A top view of a power semiconductor device according to a third embodiment is shown; Figure 5 A top view of a power semiconductor device according to a fourth embodiment is shown; Figure 6A A power semiconductor device according to the fifth embodiment is shown in a vertical cross-sectional view; Figure 6B A top view of a power semiconductor device according to a fifth embodiment is shown; Figure 6C A horizontal cross-sectional view of a power semiconductor device according to a fifth embodiment is shown; and Figure 6D Another horizontal cross-sectional view of the power semiconductor device according to the fifth embodiment is shown.

[0040] The reference numerals used in the accompanying drawings and their meanings are summarized in the list of reference numerals. Generally, similar elements have the same reference numerals throughout the specification. The described embodiments are intended as examples and should not limit the scope of the invention. Detailed Implementation

[0041] Below, refer to Figure 2A , 2B The power semiconductor device 100 according to the first embodiment is described in sections 1, 2, and 2C. Figure 2A Along Figure 2BThe power semiconductor device 100 is shown in a vertical cross-sectional view along line II-II' (which shows a top view of the power semiconductor 100), and along... Figure 2C The power semiconductor device 100 is shown in the vertical cross-sectional view along line III-III'. Figure 2C It shows along Figure 2A A horizontal cross-sectional view of the power semiconductor device 100 along line I-I'.

[0042] The power semiconductor device 100 includes a semiconductor wafer 110 having a first main side 111 and a second main side 112 opposite to the first main side 110. A thyristor structure 50 and a bipolar junction transistor (BJT) 60 are integrated in the semiconductor wafer 100, and the thyristor structure and the BJT are laterally separated from each other by an n-type separation region 80.

[0043] Throughout this specification, the first main side 111 and the second main side 112 of the semiconductor wafer 110 should be understood as planes, which include the outermost flat surface portions on the two opposite sides of the semiconductor wafer 110.

[0044] The thyristor structure 50 includes, in order from the first main side 111 to the second main side 112, an n-type first emitter layer 154, a p-type first base layer 155, an n-type second base layer 159, and a p-type second emitter layer 158. The first emitter layer 154 is in direct contact with the first base layer 155 to form a first pn junction between the first base layer 155 and the first emitter layer 154. The first base layer 155 is in direct contact with the second base layer 159 to form a second pn junction between the first base layer 155 and the second base layer 159. The second base layer 159 is in direct contact with the second emitter layer 158 to form a third pn junction between the second base layer 159 and the second emitter layer 158. The second emitter layer 158 is separated from the first base layer 155 through the second base layer 159. The second base layer 159 includes a thyristor drift layer portion 156a and a thyristor buffer layer portion 157a in the order from the first base layer 155 to the second emitter layer 158. The thyristor drift layer portion 156a is in direct contact with the first base layer 155, while the thyristor buffer layer portion 157a is in direct contact with the second emitter layer 158. The thyristor buffer layer portion 157a is perpendicularly separated from the first base layer 155 through the thyristor drift layer portion 156a. The thyristor structure 50 also includes a gate electrode 161, a first main electrode 162, and a second main electrode 163. The gate electrode 161 is arranged laterally relative to the first emitter layer 154 and forms an ohmic contact with the first base layer 155. The first main electrode 162 is arranged on the first main side 111 and forms an ohmic contact with the first emitter layer 154. The second main electrode 163 is arranged on the second main side 112 and forms an ohmic contact with the second emitter layer 158.

[0045] The BJT 60 is arranged laterally relative to the thyristor structure 50. It includes a base electrode 171 electrically separated from the gate electrode 161, a third main electrode 172 disposed on a first main side 111, and a fourth main electrode 173 disposed on a second main side 112. The base electrode 171 corresponds to the base terminal of the BJT 60, the third main electrode 172 corresponds to one of the collector terminal and the emitter terminal of the BJT 60, and the fourth main electrode 173 corresponds to the other of the collector terminal and the emitter terminal of the BJT 60. The BJT 60 includes, in order from the first main side 111 to the second main side 112, an n-type third emitter layer 184, a p-type third base layer 185, an n-type transistor drift layer portion 156b, an n-type transistor buffer layer portion 157b, and an n-type collector layer 188. The third base layer 185 is connected to the third emitter layer 184 to form a first base-emitter pn junction, the transistor drift layer portion 156b is connected to the third base layer 185 to form a drift layer-base pn junction, and the collector layer 188 is separated from the transistor drift layer portion 156b in the vertical direction (the direction extending from the first main side to the second main side) through the transistor buffer layer portion 157b, that is, the collector layer 188 is connected to the transistor drift layer 156b through the transistor buffer layer portion 157b.

[0046] exist Figure 2A In the first embodiment shown, drift layer 156 and buffer layer 157 extend laterally across the entire semiconductor wafer 110 in the power semiconductor device 100. Therefore, drift layer 56 and buffer layer 157 are shared by thyristor structure 50, BJT 60, and separation region 80. Thyristor drift layer portion 156a is a first portion of drift layer 156, and transistor drift layer portion 156b is a second portion of drift layer 156. Similarly, thyristor buffer layer portion 157a is a first portion of buffer layer 157, and transistor buffer layer portion 157b is a second portion of buffer layer 157. A third portion of drift layer 156 forms part of separation region 80 and laterally separates thyristor drift layer portion 156a from transistor drift layer portion 156b. Similarly, a third portion of buffer layer forms part of separation region 80 and laterally separates thyristor buffer layer portion 157a from transistor buffer layer portion 157b.

[0047] Both the collector layer 188 and the buffer layer 157 have higher doping concentrations than the drift layer 156. Specifically, the buffer layer 157 may have a doping concentration that rises towards the second main side 112, while the drift layer 156 typically has a constant doping concentration lower than that of the buffer layer 157. Throughout this specification, the term "doping concentration" refers to the net doping concentration. Furthermore, throughout this specification, the doping concentration of a layer refers to the local doping concentration given a description of the doping distribution of that layer. If no doping distribution is described, the doping concentration of a layer refers to the maximum doping concentration within that layer unless otherwise stated.

[0048] The third main electrode 172 forms an ohmic contact with the third emitter layer 184, the fourth main electrode 173 forms an ohmic contact with the collector layer 188, and the base electrode 171 is arranged laterally relative to the third emitter layer 184 and forms an ohmic contact with the third base layer 185.

[0049] The thyristor structure 50 includes a gate commutated thyristor (GCT) device, which includes multiple thyristor units 50a and 50b. In the first embodiment, each thyristor unit 50a, 50b includes portions 154a, 154b of a first emitter layer 154, a portion of a first base layer 155 (where portions 154a, 154b of the first emitter layer 154 are in direct contact with the portion of the first base layer 155 to form a portion of a first pn junction between the first base layer 155 and the first emitter layer 154), a portion of a second base layer 159 (where the portion of the first base layer 155 is in direct contact with the portion of the second base layer 159 to form a portion of a second pn junction between the first base layer 155 and the second base layer 159), and a portion of a second emitter layer 158 (this portion is perpendicularly separated from the portion of the first base layer 155 by the portion of the second base layer 159, wherein the portion of the second base layer 159 is in direct contact with the portion of the second emitter layer 158 to form a portion of a third pn junction between the second base layer 159 and the second emitter layer 158). The thyristor structure 50 further includes: a portion of a gate electrode 161, which is laterally arranged relative to portions 154a and 154b of the first emitter layer 154 and forms an ohmic contact with that portion of the first base layer 155; portions 162a and 162b of the first main electrode 162, which form ohmic contacts with portions 154a and 154b of the first emitter layer 154; and a portion of the second main electrode 163, which forms an ohmic contact with that portion of the second emitter layer 158. The portions 154a and 154b of the first emitter layer 154 of each thyristor unit 50a, 50b are laterally separated from the portions 154a and 154b of the first emitter layer 154 of each other thyristor unit 50a, 50b. Figure 2BThe top view best shows that portions 154a and 154b of the first emitter layer 154 are strip-shaped and arranged in two rings around the lateral center C of the circular semiconductor wafer 110. The longitudinal principal axis of each strip-shaped portion 154a and 154b of the first emitter layer 154 is aligned along a radial direction extending from the lateral center C of the semiconductor wafer 110 towards the circumferential edge region 130. Specifically, the longitudinal principal axis of each strip-shaped portion 154a and 154b of the first emitter layer 154 is defined as an axis extending in the direction where the strip-shaped portion 154a and 154b has its maximum width. Figure 2B In the top view shown, each strip portion 154a, 154b of the first emitter layer 154 and the corresponding strip portions 162a, 162b above the strip portions 154a, 154b are laterally surrounded by a gate electrode 161 of a continuous metallization layer. On the lateral outer edge of the thyristor structure 50, the gate electrode 161 includes an annular first common gate contact region 165 for connecting the gate electrode 161 to the first control unit GU1, described later. Figure 2A As illustrated in the diagram.

[0050] Similar to the thyristor structure 50, the BJT 60 also has a unit structure with multiple BJT units 60a, all of which have the same basic structure. Figure 2A One of the multiple BJT units 60a is shown in the cross-sectional view. Figure 2B In the diagram, the BJT unit 60a is indicated by a dashed line. For example... Figure 2A and Figure 2BAs shown, each BJT cell 60a includes a portion of a base electrode 171, a strip portion 172a of a third main electrode 172, and a portion of a fourth main electrode 173. This portion of the base electrode 171 corresponds to the base terminal of the BJT cell 60a, the portion 172a of the third main electrode 172 corresponds to one of the collector terminal and the emitter terminal of the BJT cell 60a, and this portion of the fourth main electrode 173 corresponds to the other of the collector terminal and the emitter terminal of the BJT cell 60a. The BJT cell 60a also includes, in order from the first main side 111 to the second main side 112, a strip portion 184a of a third emitter layer 184, a portion of a third base layer 185, a portion of a transistor drift layer portion 156b, a portion of a transistor buffer layer portion 157b, and a portion of a collector layer 188. A portion of the third base layer 185 is connected to a portion of the third emitter layer 184 to form a portion of the first base-emitter pn junction. A portion of the transistor drift layer portion 156b is connected to a portion of the third base layer 185 to form a portion of the drift layer-base pn junction. A portion of the collector layer 188 is separated from a portion of the transistor drift layer portion 156b in the vertical direction (the direction extending from the first main side to the second main side) via a portion of the transistor buffer layer portion 157b; that is, a portion of the collector layer 188 is connected to a portion of the transistor drift layer portion 156b via a portion of the transistor buffer layer portion 157b. In its lateral central portion, the base electrode 162 includes a circular second common gate contact region 175 for connecting the base electrode 171 to the second control unit GU1, described later. Figure 2A As illustrated in the diagram.

[0051] The depth d1 of the first base layer 155 (extending from the first main side 111 to this depth d1) (i.e., the depth d1 of the first base layer 155 should be understood as the maximum distance between the first main side 111 and the point within the first base layer 155) is the same as the depth d2 of the third base layer 185 (extending from the first main side 111 to this depth d2) (i.e., the depth d2 of the third base layer 185 should be understood as the maximum distance between the first main side 110 and the point within the third base layer 185).

[0052] Furthermore, the first base layer 155 may have the same vertical doping concentration distribution at the first lateral position as the third base layer 185 at the second lateral position. At the first lateral position, the lateral gradient of the doping concentration of the first base layer 155 is zero for all vertical positions, and at the second lateral position, the lateral gradient of the doping concentration of the third base layer 185 is zero for all vertical positions.

[0053] The ratio between the BJT area and the thyristor area can be in the range of 0.1 to 0.3 or in the range of 0.15 to 0.25, wherein the thyristor area is defined as the area occupied by the first base layer 155 of the thyristor structure 50 in the horizontal projection on the plane parallel to the second main side 112, and wherein the BJT area is defined as the area occupied by the third base layer 185 in the horizontal projection on the plane parallel to the second main side 112.

[0054] like Figure 2A As schematically shown, the first main electrode 162 is electrically connected to the third main electrode 172, and the second main electrode 163 is electrically connected to the fourth main electrode 173. Specifically, both the first main electrode 162 and the second main electrode 163 are electrically connected to the cathode terminal K of the power semiconductor device 100, and both the second main electrode 163 and the fourth main electrode 173 are electrically connected to the anode terminal A of the power semiconductor device 100.

[0055] A first control unit GU1 electrically connected to the gate electrode 161 is configured to control the voltage or current applied to the gate electrode 161, while a second control unit GU2 electrically connected to the base electrode 171 is electrically configured to control the current or voltage applied to the base electrode 171.

[0056] The first control unit GU1 and the second control unit GU2 are configured to first turn on the BJT 60 when the thyristor structure 50 is in a forward blocking state, then turn on the thyristor structure 50 from the forward blocking state to the forward conducting state, and then turn off the bipolar junction transistor 60 while keeping the thyristor structure 50 in the forward conducting state. This control of the thyristor structure 50 and the BJT 60 allows for safe operation of the thyristor structure 50 without the use of additional protection circuitry.

[0057] The following will refer to Figures 3A to 3C A power semiconductor device 200 according to a second embodiment is described. Figure 3A Along Figure 3B The power semiconductor device 100 is shown in a vertical cross-sectional view along line II-II' (which shows a top view of the power semiconductor 100), and along... Figure 2C The power semiconductor device 100 is shown in the vertical cross-sectional view along line III-III'. Figure 2C It shows along Figure 3AThe image shows a horizontal cross-sectional view of the power semiconductor device 100 along line I-I'. Due to the numerous similarities between the power semiconductor device 100 according to the first embodiment and the power semiconductor device 200 according to the second embodiment, the description of the power semiconductor device 200 will focus on the differences, while reference will be made to the above description of the first embodiment regarding all remaining features. Specifically, unless otherwise stated, in Figures 2A to 2C and Figures 3A to 3C Elements with the same reference symbol should have the same characteristics.

[0058] The power semiconductor device 200 according to the second embodiment differs from the power semiconductor device 100 according to the first embodiment in that, in addition to the thyristor structure 50 and the BJT 60, it also includes a freewheeling diode structure 90 integrated in the semiconductor wafer 210 having a first main side 211 and a second main side 212. The freewheeling diode structure 90 includes, in order from the first main side 211 to the second main side, a p-type first diode layer 191, an n-type diode drift layer portion 156c, an n-type semiconductor buffer layer portion 157c, and an n-type diode cathode layer 192a. The n-type diode drift layer portion 156c, the n-type diode buffer layer portion 157c, and the n-type diode cathode layer 192a form an n-type second diode layer. A pn ​​junction is formed between the n-type drift layer portion 156c and the first diode layer 191, that is, between the first diode layer 190 and the second diode layer 192. In the top view, the freewheeling diode structure 90 is ring-shaped and arranged laterally between the thyristor structure 50 and the BJT 60.

[0059] Although in the first embodiment the separation region 80 is arranged between the thyristor structure 50 and the BJT 60, in the second embodiment the first separation region 80a is laterally inserted between the freewheeling diode structure 90 and the thyristor structure 50, and the second separation region 80b is laterally inserted between the freewheeling diode structure 90 and the BJT 60. Both the first separation region 80a and the second separation region 80b separate the thyristor structure 50 from the BJT 60. Each of the first separation region 80a and the second separation region 80b may have a structure similar to that of the separation region 80 in the first embodiment. Each of the first separation region 80a and the second separation region 80b is a separation region as defined above.

[0060] In the second embodiment, the drift layer 156 and the buffer layer 157 extend laterally through the entire semiconductor wafer 210, as in the first embodiment. Similarly, similar to the first embodiment, the thyristor drift layer portion 156a is the first portion of the drift layer 156, and the transistor drift layer portion 156b is the second portion of the drift layer 156. Additionally, the transistor drift layer portion 156c is the third portion of the drift layer 156, and the first separation region 80a and the second separation region 80b respectively include the fourth and fifth portions of the drift layer 156. As in the first embodiment, the thyristor buffer layer portion 157a is the first portion of the buffer layer 157, and the transistor buffer layer portion 157b is the second portion of the buffer layer 157. Additionally, the diode buffer layer portion 157c is the third portion of the buffer layer 157, and the first separation region 80a and the second separation region 80b respectively include the fourth and fifth portions of the buffer layer 157.

[0061] Below, refer to Figure 4 Describing the power semiconductor device 200' according to the third embodiment, Figure 4 A top view of the power semiconductor device 200' is shown. Due to the numerous similarities between the power semiconductor device 200' according to the second embodiment and the power diode device 200' according to the third embodiment, the description of the power semiconductor device 200' will focus on the differences, while reference will be made to the above description of the second embodiment regarding all remaining features. Specifically, unless otherwise indicated, in Figures 3A to 3C and Figure 4Elements with the same reference numerals should have the same characteristics and properties. The only difference between power semiconductor device 200' and power semiconductor device 200 is the different arrangement of the freewheeling diode structure 90' ​​relative to the thyristor structure 50' and BJT 60' in semiconductor wafer 210'. In the cross-sectional view, the thyristor structure 50', BJT 60', and freewheeling diode structure 90' ​​appear identical to the thyristor structure 50, BJT 60, and freewheeling diode structure 90 in the second embodiment described above. Although in the second embodiment, the freewheeling diode structure 90 is laterally arranged between the outer thyristor structure 50' and the central BJT 60', the freewheeling diode 90' ​​in semiconductor power device 200' is arranged in the laterally central region of semiconductor wafer 210', and the BJT 60' is laterally arranged between the thyristor structure 50' and the central freewheeling diode structure 90' ​​adjacent to the circumferential edge region 130' of semiconductor wafer 210'. Furthermore, while in the second embodiment the second common gate contact region 165 is laterally arranged in the central region of the BJT 60, in the third embodiment the second common gate contact region 165' is laterally arranged in the outer peripheral edge of the BJT 60'. The first separation region 80a' is inserted between the central freewheeling diode structure 90' ​​and the BJT 60', while the second separation region 80' is inserted between the BJT 60 and the outer thyristor structure 50'. The first separation region 80a' and the second separation region 80b' have the same structure in cross-sectional view as the first separation region 80a and the second separation region 80b in the second embodiment, but are inserted between different entities. The second separation region 80b' is a separation region as defined above.

[0062] The following reference Figure 5 Describing the power semiconductor device 200'' according to the fourth embodiment, Figure 5 A top view of the power semiconductor device 200'' is shown. Due to the numerous similarities between the power semiconductor device 200 according to the second embodiment and the power semiconductor device 200'' according to the fourth embodiment, the description of the power semiconductor device 200'' will focus on the differences, while reference will be made to the above description of the second embodiment regarding all remaining features. Specifically, unless otherwise indicated, in Figures 3A to 3C and Figure 5Elements with the same reference numerals should have the same characteristics and properties. The only difference between power semiconductor device 200'' and power semiconductor device 200 is the different arrangement of the freewheeling diode structure 90'' relative to the thyristor structure 50'' and BJT 60'' in semiconductor wafer 210''. In the cross-sectional view, the thyristor structure 50'', BJT 60'', and freewheeling diode structure 90'' appear substantially the same as the thyristor structure 50, BJT 60, and freewheeling diode structure 90 in the second embodiment described above. Although in the second embodiment the freewheeling diode structure 90 is arranged laterally between the outer thyristor structure 50 and the central BJT 60, in power semiconductor device 200', the freewheeling diode 90' ​​is arranged adjacent to the circumferential edge region 130'' of semiconductor wafer 210'' to surround both the BJT 60'' and the thyristor structure 50''. A BJT 60'' is laterally arranged between the thyristor structure 50'' and the outer freewheeling diode structure 90'' in the lateral central region of the semiconductor wafer 210''. A first separation region 80a'' is laterally inserted between the central BJT 60'' and the thyristor structure 50'', and a second separation region 80b'' is laterally inserted between the thyristor structure 50'' and the freewheeling diode structure 90''. The first separation region 80a'' and the second separation region 80b'' have the same structure in cross-sectional view as the first separation region 80a and the second isolation region 80b in the second embodiment, but are inserted between different entities. The first separation region 80a'' is the separation region as defined above.

[0063] The following reference Figures 6A to 6D A power semiconductor device 300 according to a fifth embodiment is described. Figure 6A Along Figure 6B The power semiconductor device 300 is shown in the vertical cross-sectional view along line II-II'. Figure 6B The power semiconductor 300 is shown in a top view. Figure 6A The cross-sectional view shown is also along... Figure 6C (It shows the power semiconductor device 100 along) Figure 6A The horizontal cross-sectional view of line I-I' in the middle) and the cross-sectional view of line III-III' in the middle, and is along the Figure 6D A cross-sectional view of line IV-IV' in the diagram. Figure 6D The power semiconductor device 300 is shown along Figure 6A A horizontal cross-sectional view along line V-V'. Due to the numerous similarities between the power semiconductor device 100 according to the first embodiment and the power semiconductor device 300 according to the fifth embodiment, the description of the power semiconductor device 300 will focus on the differences, while reference will be made to the above description of the first embodiment regarding all remaining features. Specifically, unless otherwise indicated, in Figures 2A to 2C and Figures 6A to 6D Components with the same reference numerals should have the same characteristics and properties.

[0064] The power semiconductor device 300 includes a semiconductor wafer 310 having a first main side 311 and a second main side 312. It includes a thyristor structure 50, a BJT 360, and a separation region 80 laterally inserted between the thyristor structure 50 and the BJT 360. The power semiconductor device 300 differs from the power semiconductor device 100 in that the BJT 360 has a different structure than the BJT 60 in the first embodiment. Similar to the BJT 60, the BJT 360 includes a base electrode 371 electrically separated from the gate electrode 171, a third main electrode 372 disposed on the first main side 311, and a fourth main electrode 373 disposed on the second main side 312. The base electrode 371 corresponds to the base terminal of the bipolar junction transistor 360, the third main electrode 372 corresponds to the collector terminal of the bipolar junction transistor 360, and the fourth main electrode 373 corresponds to the emitter terminal of the bipolar junction transistor 360. The BJT 360 includes, within a semiconductor wafer 310, a p-type collector layer 388 disposed adjacent to a first main side 311, an n-type third base layer 385 disposed adjacent to a second main side 312, a p-type third emitter layer 384 disposed laterally relative to the third base layer 385 adjacent to the second main side 312, an n-type transistor drift layer portion 156b, and an n-type transistor buffer layer portion 157b. The transistor drift layer portion 156b and the transistor buffer layer portion 157b are both disposed between the collector layer 388 and each of the third base layer 384 and the third emitter layer 385. The collector layer 388 is connected to the drift layer 156 via a collector-drift layer pn junction, the third base layer 385 is connected to the drift layer 156 via a buffer layer 157, and the third base layer 385 is connected to the third emitter layer via a second base-emitter pn junction. The third main electrode 372 forms an ohmic contact with the collector layer 388, the fourth main electrode 371 forms an ohmic contact with the third emitter layer 384, and the base electrode 371 is arranged laterally relative to the fourth main electrode 373 and forms an ohmic contact with the third base layer 385.

[0065] The collector layer 188 includes a first collector layer portion 88a and a second collector layer portion 88b in sequence from the first main side 311 toward the second main side 312, wherein the second collector layer portion 88b has a similar doping distribution in the vertical direction as the first base layer 155 in the vertical direction. The depth d1 of the first base layer 155 (extending from the first main side 311 to this depth) can be the same as the depth d3 of the collector layer 388 (extending from the first main side 311 to this depth of the second collector layer 388). The depth d4 of the second emitter layer 158 (extending from the second main side 312 to this depth of the second emitter layer 158) is the same as the depth d5 ​​of the third emitter layer 384 (extending from the second main side 312 to this depth of the third emitter layer 384).

[0066] It will be apparent to those skilled in the art that modifications to the above embodiments are possible without departing from the spirit of the invention as defined above.

[0067] Different lateral arrangements of thyristor structures 50, 50', 50'', BJTs 60, 60', 60'', 360, and freewheeling diodes 90, 90', 90'' have been described. However, other lateral arrangements are also possible. Furthermore, the present invention is not limited to the specific unit structures of thyristor structures 50, 50', 50'' and BJTs 60, 60', 60'', 360. Moreover, although freewheeling diodes 90, 90', 90'' are described as having a single continuous first diode layer 291 and a single continuous second diode layer 292, the freewheeling diodes can have any other segmented unit structure.

[0068] The semiconductor wafer of the power semiconductor device of the present invention can be made of silicon (Si) or any other suitable semiconductor material.

[0069] In the above embodiments, the first control unit (GU1) and the second control unit (GU2) can be implemented in a single control unit that has the functions of both control units GU1 and GU2.

[0070] The above embodiments are explained using specific conductivity types. The conductivity types of the semiconductor layers in the above embodiments can be switched, such that all layers described as p-type layers are n-type layers, and all layers described as n-type layers are p-type layers. It should be noted that the word "comprising" does not exclude other elements or steps, and the indefinite articles "a" or "an" do not exclude the plural. Elements described in association with different embodiments can also be combined.

[0071] Reference Symbol List 1. Reverse-guided IGCT (RC-IGCT) 2 thyristor units 3 Integrated freewheeling diodes 10 chips 11 First Main Side 12 Second Main Side 20 gate electrode 21 First cathode electrode 22 Cathode semiconductor layer section 23 base semiconductor layer 24 Drift Semiconductor Layers 25 Buffer Semiconductor Layer 26 First Anode Semiconductor Layer 27 First anode electrode 31 Second anode electrode 32 Second anode semiconductor layer 33 Second cathode semiconductor layer 34 Second cathode electrode 50 thyristor structure 50a, 50b thyristor units 60, 360 bipolar junction transistors (BJTs) 60A Bipolar Junction Transistor (BJT) Unit 80 separation zone 80a, 80a', 80a'' First separation zone 80b, 80b', 80b'' Second separation zone 88a First Collector Layer 88b second collector layer section 90, 90', 90'' freewheeling diodes 100, 200, 200', 200'', 300 power semiconductor devices 110, 210, 210', 310 semiconductor wafers 111, 211, 311 First Main Side 112, 212, 312 Second Main Side 130, 130', 130'' edge area 154 First Emitter Layer Part of the first emitter layer of 154a and 154b 155 First base layer 156 drift layers 156a thyristor drift layer section 156b transistor drift layer section 156c diode drift layer section 157 buffer layers 157a thyristor buffer layer section 157b transistor buffer layer section 157c diode buffer layer section 158 Second Emitter Layer 159 Second base layer 161, 161', 161'' gate electrodes 162, 162', 162'' First main electrode The first main electrode portions of 162a and 162b 163 Second Main Electrode 165, 165', 165'' First common gate contact region 171, 171', 171'', 371 base electrode 172, 172', 172'', 372 Third main electrode The strip-shaped portion of the third main pole of 172a 173,373 Fourth main electrode 175, 175', 175'' Second common gate contact region 184,384 Third emitter layer 185, 385 Third base layer 188,388 collector layers 191 First Diode Layer 192 Second Diode Layer 192a diode cathode layer 193 diode anode electrode 194 diode cathode electrode Depths d1, d2, d3, d4, and d5

Claims

1. A power semiconductor device, comprising: Semiconductor wafers (110; 210; 210’； 210’’； 310), the semiconductor wafer has a first main side (111; 211; 311) and a second main side (112; 212; 312) opposite to the first main side (111; 211; 311); and The thyristor structure (50; 50'; 50'') comprises, in the order from the first main side (111; 211; 311) to the second main side (112; 212; 312): • First emitter layer (154) of the first conductivity type; • A first base layer (155) of a second conductivity type different from the first conductivity type, wherein the first emitter layer (154) is in direct contact with the first base layer (155) to form a first pn junction between the first base layer (155) and the first emitter layer (154); • A second base layer (159) of a first conductivity type, wherein the first base layer (155) is in direct contact with the second base layer (159) to form a second pn junction between the first base layer (155) and the second base layer (159); and • A second emitter layer (158) of the second conductivity type, wherein the second emitter layer (158) is separated from the first base layer (155) through the second base layer (159), wherein the second base layer (159) is in direct contact with the second emitter layer (158) to form a third pn junction between the second base layer (159) and the second emitter layer (158). The thyristor structure (50; 50'; 50'') further includes: • Gate electrode (161), which is laterally arranged relative to the first emitter layer (154) and forms an ohmic contact with the first base layer (155); • A first main electrode (162), disposed on the first main side (111; 211; 311), and forming an ohmic contact with the first emitter layer (154); and • The second main electrode (163) is disposed on the second main side (112; 212; 312) and forms an ohmic contact with the second emitter layer (158). The power semiconductor device further includes bipolar junction transistors (60; 60'; 60''; 360) arranged laterally relative to the thyristor structure (50; 50'; 50''). The bipolar junction transistor (60; 60'; 60''; 360) includes a base electrode (171; 171'; 171''; 371) electrically separated from the gate electrode (161), a third main electrode (172; 172'; 172''; 372) disposed on the first main side (111; 211; 311), and a fourth main electrode (173; 373) disposed on the second main side (112; 212; 312). Wherein, the base electrode (171; 171'; 171''; 371) corresponds to the base terminal of the bipolar junction transistor (60; 60'; 60''; 360), and The third main electrode (172; 172'; 172''; 372) corresponds to one of the collector terminal and the emitter terminal of the bipolar junction transistor (60; 60'; 60''; 360), and the fourth main electrode (173; 373) corresponds to the other of the collector terminal and the emitter terminal of the bipolar junction transistor (60; 60'; 60''; 360). The first main electrode (162; 162'; 162'') is electrically connected to the third main electrode (172; 172'; 172''; 372), and the second main electrode (163) is electrically connected to the fourth main electrode (173; 373).

2. The power semiconductor device according to claim 1, wherein, The semiconductor wafer (110; 210; 210'; 210''; 310) includes separation regions (80; 80a, 80b; 80b'; 80a'') of a first conductivity type, wherein the separation regions (80; 80a; 80b; 80b'; 80a'') are laterally arranged between the bipolar junction transistor (60; 60'; 60''; 360) and the thyristor structure (50; 50'; 50'') to separate the bipolar junction transistor (60; 60'; 60''; 360) from the thyristor structure (50; 50'; 50'') by at least the separation regions (80; 80a; 80b).

3. The power semiconductor device according to any one of the preceding claims, wherein, The semiconductor wafer (210; 210'; 210'') includes a freewheeling diode (90; 90'; 90'') arranged laterally relative to the thyristor structure (50; 50'; 50'') and relative to the bipolar junction transistor (60; The freewheeling diodes (90'; 60'') are arranged laterally. 90'; 90'') includes, in order from the first main side (211) to the second main side (212): a first diode layer (191) of the second conductivity type and a second diode layer (192) of the first conductivity type, wherein the second diode layer (192) and the first diode layer (191) form a fourth pn junction.

4. The power semiconductor device according to claim 1 or 2, wherein, The second base layer (159) includes a relatively lightly doped thyristor drift layer portion (156a) and a thyristor buffer layer portion (157a) having a higher doping concentration than the thyristor drift layer portion (156a), wherein the thyristor buffer layer portion (157a) separates the thyristor drift layer portion (156a) from the second emitter layer (158).

5. The power semiconductor device according to claim 1 or 2, wherein, The thyristor structure (50; 50'; 50'') includes a gate-commutated thyristor (GCT) device, and the gate-commutated thyristor device includes multiple thyristor units (50a, 50b).

6. The power semiconductor device according to claim 5, wherein, Each thyristor unit (50a, 50b) includes: • A portion of the first emitter layer (154) (154a, 154b). • A portion of the first base layer (155), wherein the portions (154a, 154b) of the first emitter layer (154) are in direct contact with the portions of the first base layer (155) to form a portion of the first pn junction between the first base layer (155) and the first emitter layer (154). • A portion of the second base layer (159), wherein the portion of the first base layer (155) is in direct contact with the portion of the second base layer (159) to form a portion of the second pn junction between the first base layer (155) and the second base layer; and • A portion of the second emitter layer (158), wherein the portion of the second emitter layer is separated from the portion of the first base layer (155) by the second base layer (159), wherein the portion of the second base layer (159) is in direct contact with the portion of the second emitter layer (158) to form a portion of the third pn junction between the second base layer (159) and the second emitter layer (158). The thyristor structure (50; 50'; 50'') further includes: • A portion of the gate electrode (161) is arranged laterally relative to the portions (154a, 154b) of the first emitter layer (154) and forms an ohmic contact with the portion of the first base layer (155). • A portion (162a, 162b) of the first main electrode (162) forms an ohmic contact with a portion (154a, 154b) of the first emitter layer (154); and • A portion of the second main electrode (163) forms an ohmic contact with a portion of the second emitter layer (158), and The portion (154a, 154b) of the first emitter layer (154) of each thyristor unit (50a, 50b) is laterally separated from the portion (154a, 154b) of the first emitter layer (154) of each other thyristor unit (50a, 50b).

7. The power semiconductor device according to claim 1, wherein, The bipolar junction transistors (60; 60'; 60'') include, in order from the first main side (111; 211) to the second main side (112; 212): • The third emitter layer of the first conductivity type (184); • A third base layer (185) of the second conductivity type, wherein the third base layer (185) is connected to the third emitter layer (184) through a first base-emitter pn junction; • A first conductivity type transistor drift layer portion (156b), said transistor drift layer portion (156b) being connected to the third base layer (185) via a drift layer-base pn junction; and • A collector layer (188) of a first conductivity type, having a higher doping concentration than the transistor drift layer portion (156b) and being in direct contact with or connected to the transistor drift layer portion (156b) through a transistor buffer layer portion (157b) of the first conductivity type, the transistor buffer layer portion (157b) having a higher doping concentration than the transistor drift layer portion (156b). The third main electrode (172; 172'; 172'') forms an ohmic contact with the third emitter layer (184). The fourth main electrode (173) forms an ohmic contact with the collector layer (188), and The base electrode (171; 171'; 171'') is arranged laterally relative to the third emitter layer (184) and forms an ohmic contact with the third base layer (185).

8. The power semiconductor device according to claim 7, wherein, The depth (d1) to which the first base layer (155) extends from the first main side (111; 211) is the same as the depth (d2) to which the third base layer (185) extends from the first main side (111; 211).

9. The power semiconductor device according to claim 8, wherein, The first base layer (155) has the same vertical doping concentration distribution at the first lateral position as the third base layer (185) at the second lateral position. At the first lateral position, the lateral gradient of the doping concentration of the first base layer (155) is zero for all vertical positions, and at the second lateral position, the lateral gradient of the doping concentration of the third base layer (185) is zero for all vertical positions.

10. The power semiconductor device according to any one of claims 7 to 9, wherein, The ratio between the area of ​​the bipolar junction transistor and the area of ​​the thyristor is in the range of 0.1 to 0.3 or in the range of 0.15 to 0.25, wherein the thyristor area is defined as the area occupied by the first base layer (155) of the thyristor structure (50; 50'; 50'') in a horizontal projection on a plane parallel to the second main side (112; 212), and wherein the area of ​​the bipolar junction transistor is defined as the area occupied by the third base layer (185) in a horizontal projection on a plane parallel to the second main side (112; 212).

11. The power semiconductor device according to claim 1, wherein, The bipolar junction transistor (360) includes: • A collector layer (388) of a second conductivity type is arranged adjacent to the first main side (311); • A third base layer (385) of a first conductivity type is arranged adjacent to the second main side (312); • A third emitter layer (384) of the second conductivity type, the third emitter layer (384) being arranged adjacent to the second main side (312) and laterally relative to the third base layer (385); and • A transistor drift layer portion (156b), which is disposed between each of the third base layer (385) and the third emitter layer (384) and the collector layer (388). The collector layer (388) is connected to the transistor drift layer portion (156b) through a collector-drift layer pn junction. The third base layer (385) is in direct contact with the transistor drift layer portion (156b) or connected to the transistor drift layer portion (156b) through a transistor buffer layer portion (157b) of the first conductivity type. The transistor buffer layer portion (157b) has a higher doping concentration than the transistor drift layer portion (156b). The third base layer (385) is connected to the third emitter layer (384) through the second base-emitter pn junction. The third main electrode (372) forms an ohmic contact with the collector layer (388). The fourth main electrode (373) forms an ohmic contact with the third emitter layer (384), and The base electrode (371) is arranged laterally relative to the fourth main electrode (373) and forms an ohmic contact with the third base layer (385).

12. The power semiconductor device according to claim 11, wherein, The depth (d1) to which the first base layer (155) extends from the first main side (311) is the same as the depth (d3) to which the collector layer (388) extends from the first main side (311).

13. The power semiconductor device according to claim 11 or 12, wherein, The second emitter layer (158) extends from the second main side (312) to the same depth (d4) as the third emitter layer (384) extends from the second main side (312) to the same depth (d5).

14. The power semiconductor device according to claim 1 or 2, comprising: A first control unit (GU1) is electrically connected to the gate electrode (161; 161'; 161'') and configured to control the voltage or current applied to the gate electrode (161; 161'; 161''); as well as A second control unit (GU2) is electrically configured to control the current or voltage applied to the base electrodes (171; 171'; 171''; 371). The first control unit (GU1) and the second control unit (GU2) are configured to first turn on the bipolar junction transistor (60; 60'; 60''; 360) when the thyristor structure (50; 50'; 50'') is in the forward blocking state, then turn on the thyristor structure (50; 50'; 50'') from the forward blocking state to the forward conducting state, and then turn off the bipolar junction transistor (60; 60'; 60''; 360) while keeping the thyristor structure (50; 50'; 50'') in the forward conducting state.

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