Semiconductor device with an active device area and a current sensor area

Abstract

A semiconductor device is provided. The semiconductor device comprises a substrate and an active device region comprising a plurality of gate grooves formed on a first primary surface of the semiconductor substrate. The semiconductor device further comprises a current sensing region comprising a plurality of gate grooves formed on the first primary surface of the semiconductor substrate. The semiconductor device further comprises a transition region located between the active device region and the current sensing region. The transition region includes an additional groove formed on the first primary surface of the semiconductor substrate. The additional groove separates the plurality of gate grooves of the active device region from the plurality of gate grooves of the current sensing region.An electrode formed in the additional trench is neither electrically connected to gate electrodes formed in the majority of gate trenches of the active device area, nor electrically connected to gate electrodes formed in the majority of gate trenches of the current sensor area.

Description

TECHNICAL AREA

[0001] The present disclosure relates to a semiconductor device comprising an active device area and a current sensor area. BACKGROUND

[0002] Some power devices incorporate current and temperature sensing mechanisms to monitor overcurrent or overtemperature operating conditions. The output of such sensing mechanisms can be routed to other control and protection circuits to manage the operation of one or more power devices. These control and protection circuits operate to disable power devices when an overcurrent or overtemperature operating condition is detected. The power devices should be properly shut down as early as possible to prevent a short circuit or overcurrent situation. Therefore, there is a need for a reliable current and temperature sensing approach for power devices, such as power semiconductor devices. SUMMARY

[0003] According to an example of a semiconductor device, the semiconductor device comprises a substrate and an active device region comprising a plurality of gate grooves formed on a first primary surface of the semiconductor substrate. The semiconductor device further comprises a current sensing region comprising a plurality of gate grooves formed on the first primary surface of the semiconductor substrate. The semiconductor device further comprises a transition region located between the active device region and the current sensing region. The transition region includes an additional groove formed on the first primary surface of the semiconductor substrate. The additional groove separates the plurality of gate grooves of the active device region from the plurality of gate grooves of the current sensing region.An electrode formed in the additional trench is neither electrically connected to gate electrodes formed in the majority of gate trenches of the active device area, nor electrically connected to gate electrodes formed in the majority of gate trenches of the current sensor area.

[0004] Experts in the field will recognize additional features and benefits upon reading the following detailed description and examining the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0005] The present disclosure is illustrated by way of example and without limitation in the figures of the accompanying drawings, in which the same reference numerals refer to similar or identical elements unless otherwise indicated. The elements of the drawings are not necessarily drawn to scale relative to one another. The features of the various examples shown may be combined, provided they are not mutually exclusive. Fig. 1A shows a partial top view of an exemplary semiconductor device; and Fig. 1B + Fig. Figure 1C shows cross-sectional views of the semiconductor device; Fig. 2- Fig. Figure 4 shows partial top views of exemplary semiconductor devices; Fig. Figure 5 shows a circuit diagram of an exemplary electronic system; Fig. Figure 6 shows a top view of a layout for an exemplary semiconductor device; and Fig. 7A + Fig. 7B, Fig. 7D + Fig. Figure 7E shows enlarged top views of exemplary semiconductor devices; and Fig. Figure 7C shows a cross-sectional view of a semiconductor device. DETAILED DESCRIPTION

[0006] The manufacture and use of various examples are discussed in detail below. It is understood, however, that the present invention provides many applicable inventive concepts that can be implemented in a variety of specific contexts. The specific examples discussed serve only to illustrate specific ways of manufacturing and using the invention and do not limit its scope.

[0007] The expressions "exhibiting," "containing," "encompassing," "comprising," and the like are open expressions, and these expressions indicate the presence of specified structures, elements, or features, but do not exclude the presence of additional elements or features. The articles "a," "an," and "the" include both the singular and the plural unless the context clearly indicates otherwise.

[0008] The terms "bonded," "attached," "connected," and / or "coupled" are not intended to imply that the elements or layers must be in direct contact with one another; intermediate elements or layers may be provided between the "bonded," "attached," "connected," and / or "coupled" elements. However, according to the disclosure, the above terms may optionally also have the specific meaning that the elements or layers are brought into direct contact with one another, i.e., that no intermediate elements or layers are provided between the "bonded," "attached," "connected," and / or "coupled" elements.

[0009] The term “electrically connected” describes a permanent low-resistance connection between electrically connected elements, for example, a direct contact between the elements in question or a low-resistance connection via a metal and / or a highly doped semiconductor material.

[0010] The terms "on" and "over" are not to be interpreted as meaning only "directly on" and "directly over". Rather, if one element is positioned "on" or "over" another element (e.g., a layer is "on" or "over" another layer, or "on" or "over" a substrate), another component (e.g., another layer) can be positioned between the two elements (e.g., another layer can be positioned between a layer and a substrate if the layer is "on" or "over" the substrate).

[0011] Spatially relative terms, such as "below," "under," "lower," "above," "upper," "below," and the like, are used here to simplify the description and to describe the relationship of one element or feature to another element(s) or feature(s), as illustrated in the figures. These spatially relative terms are intended to encompass various orientations of the device during use or operation, in addition to the orientation shown in the figures. The device may be oriented differently (rotated by 90 degrees or in other orientations), and the spatially relative descriptors used here may also be used for other purposes.

[0012] Next, exemplary implementations of a semiconductor device with an active device region and a current sensor region are described with reference to the figures. While the exemplary implementations are described in the context of IGBT (Insulated Gate Bipolar Transistor) devices, they can be realized using other types of transistors, such as MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor), BJT (Bipolar Junction Transistor), JFET (Junction Field-Effect Transistor), etc. This means that references to emitter and collector can apply equally to the source and drain of a MOSFET or similar terminals of other types of transistors.In the following implementations, the first conductivity type is n-type and the second conductivity type is p-type for an n-channel device, while the first conductivity type is p-type and the second conductivity type is n-type for a p-channel device.

[0013] Fig. Figure 1A shows a partial top view of an exemplary semiconductor device 100. Fig. 1B shows a cross-sectional view of the semiconductor device 100 along the line marked AA' in Fig. Line 1A is represented. Fig. 1C shows a cross-sectional view of the semiconductor device 100 along the line marked BB' in Fig. Line 1A is shown. It should be noted that Fig. 1A to simplify the presentation and provide a free view of fewer details than Fig. 1B + Fig. Contains 1C.

[0014] The semiconductor device 100 comprises a semiconductor substrate 102. The semiconductor substrate 102 can comprise one or more of a variety of semiconductor materials used to form semiconductor devices. For example, the semiconductor substrate 102 can comprise single-element semiconductors (e.g., Si, Ge, etc.), silicon-on-insulator semiconductors, binary semiconductors (e.g., SiC, GaN, GaAs, SiGe, etc.), and ternary semiconductors (e.g., AlGaN, InGaAs, InAlAs, etc.). The semiconductor substrate 102 can be a bulk semiconductor material or it can comprise one or more additional elements, such as epitaxial layers grown on a bulk semiconductor material, field-stop regions, buffer layers, well regions, etc. The bulk semiconductor material can be referred to as the base semiconductor. The semiconductor substrate 102 has a first main surface 104 and a second main surface 106 opposite the first main surface 104.The first main surface 104 can be called the front surface and the second main surface 106 can be called the rear surface.

[0015] The semiconductor device 100 further comprises an active device area 108 and a current sensor area 112. The active device area 108 comprises a plurality of gate trenches 110 formed on the first main surface 104 of the semiconductor substrate 102. The current sensor area 112 comprises a plurality of gate trenches 114 formed on the first main surface 104 of the semiconductor substrate 102. The semiconductor device 100 can be referred to as a trench semiconductor device. The active device area 108 comprises power transistor cells forming a power transistor of the semiconductor device 100, and the current sensor area 112 comprises current sensor transistor cells forming a current sensor transistor of the semiconductor device 100. The power transistor can be referred to as the main transistor.The current sensor cells reflect a current flowing in the active device area 108, and a current flowing through the current sensor cells can be used to detect the current flowing through the main transistor, as described below in conjunction with . Fig. 5 is described in more detail. This means that a current measured in the current sensor cells represents a current flowing through the active device area 108. The power transistor cells and the current sensor transistor cells can have the same configuration, the same spacing, etc., but with fewer current sensor transistor cells than power transistor cells, e.g., 1 / 10, 1 / 100, 1 / 1000, or even fewer cells compared to the power transistor cells.

[0016] The semiconductor device 100 further comprises a transition area 116, which is arranged between the active device area 108 and the current sensor area 112. The transition region 116 includes an additional trench 120 formed on the first main surface 104 of the semiconductor substrate 102, and the additional trench 120 separates the plurality of gate trenches 110 of the active device region 108 from the plurality of gate trenches 114 of the current sensing region 112. In one example, the transition region 116 spatially separates the plurality of gate trenches 110 of the active device region 108 from the plurality of gate trenches 114 of the current sensing region 112 within the semiconductor substrate 102, and there is no physical connection between the plurality of gate trenches 110 of the active device region 108 and the plurality of gate trenches 114 of the current sensing region 112.The transition area 116 can be referred to as the interface area and the additional trench 120 can be referred to as the isolation trench.

[0017] As seen in the cross-sectional views of Fig. 1B + Fig. As shown in Figure 1C, the current sensor area 112 comprises gate grooves 114 formed on the first main surface 104 of the semiconductor substrate 102 and extending into the semiconductor substrate 102. Similarly, the active device area 108 comprises gate grooves 110 formed on the first main surface 104 of the semiconductor substrate 102 and extending into the semiconductor substrate 102. Gate electrodes 122 are formed in the gate grooves 114 of the current sensor area 112, and the gate electrodes 122 are separated from the semiconductor substrate 102 by a gate dielectric 124. Similarly, gate electrodes 126 are formed in the gate grooves 110 of the active device area 108 and the gate electrodes 126 are separated from the semiconductor substrate 102 by a gate dielectric 128.

[0018] An electrode 130 is formed in the additional groove 120 and is separated from the semiconductor substrate 102 by a dielectric 132. The electrode 130 formed in the additional groove 120 is not electrically connected to the gate electrodes 126 formed in the gate grooves 110 of the active device area 108. Additionally, the electrode 130 formed in the additional groove 120 is not electrically connected to the gate electrodes 122 formed in the gate grooves 114 of the current sensor area 112. That is, the electrode 130, which is formed in the additional trench 120, is neither electrically connected to the gate electrodes 126, which are formed in the gate trenches 110 of the active device area 108, nor electrically connected to the gate electrodes 122, which are formed in the gate trenches 114 of the current sensor area 112.In one example, the electrode 130, which is formed in the additional trench 120, is electrically isolated from the gate electrodes 126, which are formed in the gate trenches 110 of the active device area 108. Additionally, the electrode 130, which is formed in the additional trench 120, is electrically isolated from the gate electrodes 122, which are formed in the gate trenches 114 of the current sensor area 112.

[0019] The implementation of the additional trench 120 and the implementation of the electrode 130, which is formed in the additional trench 120 and is electrically isolated from the gate electrodes 126 of the active device area 108 and from the gate electrodes 122 of the current sensor area 112, enable a reduction or suppression of a leakage current flowing from the active device area 108 to the current sensor area 112 or vice versa. In one example, the gate electrodes 126 of the active device area 108 are electrically connected to the gate electrodes 122 of the current sensor area 112. That is, the power transistor of the active device area 108 is switched on / off simultaneously with the current sensor transistor of the current sensor area 112.In one example, the power transistor and the current sensor transistor can be switched on by applying a positive voltage to gate electrodes 126 and 122, respectively. Furthermore, the power transistor and the current sensor transistor can be switched off by applying a negative voltage to gate electrodes 126 and 122, respectively. Without the presence of electrode 130 formed in the additional trench 120, as previously described, when the power transistor and the current sensor transistor are switched off, a parasitic leakage current can flow from the active device area 108 to the current sensor area 112, or vice versa. A leakage path can be formed involving body areas 136 formed on both sides of the additional trench 120, and a channel can be formed connecting the body areas 136 on both sides of the additional trench 120.The parasitic leakage current can negatively affect the operation of the semiconductor device 100 in a state where the power transistor and the current sensor transistor are switched off. For example, a temperature measurement of the semiconductor device 100 can be performed when the power transistor and the current sensor transistor are switched off. In the absence of the electrode 130, which is formed in the additional groove 120 as previously described, this temperature measurement may be inaccurate.

[0020] As shown in the cross-sectional view of Fig. As shown in Figure 1B, the current sensing region 112 comprises source regions 134 of a first conductivity type and body regions 136 of a second conductivity type, formed between adjacent gate trenches 114. The current sensing region 112 further comprises a drift region 138 of the first conductivity type and a collector region 140 of the second conductivity type. Channels form in the body regions 136 along the gate trenches 114 to provide an electrically conductive connection between the source regions 134 and the drift region 138. The channels are controlled by a voltage applied to the gate electrodes 122. It is noted that for devices other than IGBTs, such as MOSFETs, the collector region 140 of the second conductivity type is replaced by a drain region of the first conductivity type.

[0021] A first conductive layer 142 is formed over the first primary surface 104 of the semiconductor substrate 102. The first conductive layer 142 is segmented, and one segment of the conductive layer 142 contacts the source regions 134 and the body regions 136. This segment is electrically isolated from the gate electrodes 122 by a segmented dielectric intermediate layer 144, which is formed over the first primary surface 104 of the semiconductor substrate 102. A second conductive layer 146 is formed over the second primary surface 106 of the semiconductor substrate 102 to provide a collector potential for the collector region 140. The first conductive layer 142 and / or the second conductive layer 146 can be a metallization layer.

[0022] As explained above, the current sensing cells located in the current sensing region 112 reflect the current flowing in the power transistor cells in the active device region 108 and have a similar or identical cell configuration to the power transistor cells, albeit with a lower cell count. This means that the active device region 108 comprises first-type conductivity source regions, second-type conductivity body regions, a first-type conductivity drift region, and first and second conducting layers, depicted and described similarly to those for the current sensing region 112. In one example, the electrode 130 formed in the additional trench 120 is electrically connected to the source regions of the active device region 108.The electrode 130 is electrically isolated from the gate electrodes 126 of the active device area 108 and from the gate electrodes 122 of the current sensor area 112.

[0023] The current sensor cells located in the current sensor area 112 and the power transistor cells located in the active device area 108 are configured to conduct a load current between the first main surface 104 of the semiconductor substrate 102 and the second main surface 106 of the semiconductor substrate 102. The semiconductor device 100 can be referred to as a vertical power semiconductor device and can be configured to conduct load currents of more than 1 A, more than 10 A, more than 30 A, or hundreds of A, such as in automotive applications. It can further be configured to block voltages between load terminals in the range of ten to several thousand volts, e.g., 10 V, 400 V, 650 V, 1.2 kV, 1.7 kV, 3.3 kV, 4.5 kV, 5.5 kV, 6 kV, 6.5 kV.

[0024] As in Fig. 1B + Fig. As shown in Figure 1C, the gate grooves 114 of the current sensor area 112 extend from the first main surface 104 of the semiconductor substrate 102 to a first depth d1 within the semiconductor substrate 102. Furthermore, the gate grooves 114 have a first width w1. The gate grooves 110 of the active device area 108 extend from the first main surface 104 of the semiconductor substrate 102 to a second depth d2 within the semiconductor substrate 102. Furthermore, the gate grooves 110 have a second width (not shown). In one example, the gate grooves 110 of the active device area 108 have the same width and / or depth as the gate grooves 114 of the current sensor area 112. Such a regular structure allows for simplified fabrication of the semiconductor device 100 and reduces manufacturing costs.Similarly, the additional trench 120 extends from the first main surface 104 of the semiconductor substrate 102 to a third depth d3 within the semiconductor substrate 102 and has a third width w3. In one example, the additional trench 120 has the same width and / or depth as one of the gate trenches 110 of the active device area 108 and / or one of the gate trenches 114 of the current sensor area 112.

[0025] The semiconductor device 100, as in connection with Fig. 1A- Fig. 1C, as illustrated and described, is provided as an example. Other examples may differ from what is described in relation to Fig. 1A- Fig. 1C is shown and described. For example, the shape and position of the gate trenches, source areas, body areas, and additional trench may differ from what is shown in connection with Fig. 1A- Fig. Figure 1C is shown and described. For example, contact recesses can extend from the first main surface 104 of the semiconductor substrate 102 into source and body regions to provide electrical contact to the source and body regions. Furthermore, it can include additional conductive and dielectric intermediate layers, or less conductive and dielectric intermediate layers than those shown. Fig. 1B + Fig. 1C shown etc.

[0026] Fig. Figure 2 shows another partial top view of an exemplary semiconductor device 200. Similar to the semiconductor device 100 of Fig. 1A- Fig. 1C comprises the semiconductor device 200, an active device area 208, a current sensor area 212, and a transition area 216. The transition area 216 includes an additional trench 220. The gate trenches 110 and 114 of the semiconductor device 100 of Fig. 1A- Fig. 1C are strip-shaped gate grooves arranged in parallel. The semiconductor device 200 of Fig. 2 differs from the semiconductor device 100 from Fig. 1A- Fig. 1C by gate trenches 210, 214, which are arranged in a grid shape. In one example, the grid can be rectangular; in another implementation, it can be square or hexagonal. Both the active device area 208 and the current sensor area 212 comprise grid-shaped gate trenches 210, 214. Source areas and body areas (not shown) can be arranged within the grid of gate trenches 210, 214 such that the source areas and body areas are surrounded by the gate trenches 210, 214.

[0027] The semiconductor devices 100, 200, as in connection with Fig. 1A- Fig. 1C, Fig. The examples shown and described in section 2 are provided as examples. Other examples may differ from what is described in relation to Fig. 1A- Fig. 1C, Fig. 2 is shown and described. For example, the gate ditches 110, 114, 210, 214 can be arranged such that they are neither parallel nor orthogonal to each other. Furthermore, the additional ditches 120, 220 can have a different shape than the strip shape shown in conjunction with Fig. 1A- Fig. 1C, Fig. 2 is shown and described. The trenches 110, 114, 210, 214, 120, 220 can have any kind of shape, for example an open shape, such as a straight strip, or for example a closed shape, such as a grid shape.

[0028] Fig. Figure 3 shows another partial top view of an exemplary semiconductor device 300. Similar to semiconductor devices 100, 200 of Fig. 1A- Fig. 1C, Fig. 2 The semiconductor device 300 comprises an active device region 308, a current sensor region 312, and a transition region 316 that includes an additional trench 320. However, the transition region 316 of the semiconductor device 300 also includes a further additional trench 348 that extends parallel to the additional trench 320. Similar to an electrode formed in the additional trench 320, an electrode formed in the further additional trench 348 is electrically isolated from gate electrodes of the active device region 308 as well as from gate electrodes of the current sensor region 312. In one example, the electrode of the further additional trench 348 is electrically connected to source regions of the active device region 308.The electrode contained in the additional trench 348 can enable improved reduction or prevention of leakage current flowing from the active device area 308 to the current sensor area 312 or vice versa. In one example, the additional trench 348 extends at least partially parallel to the additional trench 320.

[0029] Fig. Figure 4 shows another partial top view of an exemplary semiconductor device 400. Similar to semiconductor devices 100, 200, 300 of Fig. 1A- Fig. 1C, Fig. 2- Fig. 3 The semiconductor device 400 comprises an active device area 408, a current sensor area 412, and a transition area 416, which includes an additional trench 420. Within the semiconductor device 400, the current sensor area 412 is embedded in the active device area 408. In the example of Fig. 4 The transition area 416 and the additional trench 420 completely surround the current sensor area 412 to reduce or suppress any leakage current flowing from the active device area 408 to the current sensor area 412 or vice versa, as explained above.

[0030] In some examples, the additional trench 420 may not completely surround the current sensor area 412, as shown in Fig. Figure 4 illustrates this. Instead, the additional trench 420 can at least partially surround the current sensing area 412 to suppress a leakage current flowing from the active device area 408 to the current sensing area 412, or vice versa, as explained above. In some examples, an additional trench separates a plurality of gate trenches of the active device area 408 from a plurality of gate trenches of the current sensing area 412 at a first side S1 of the current sensing area 412. Additionally, another additional trench separates the plurality of gate trenches of the current sensing area 412 from a plurality of further gate trenches of the active device area 408 at a second side S2 of the current sensing area 412, which is opposite the first side S1.This means that there is no additional trench either on a third side S3 of the current sensor area 412 or on a fourth side S4 of the current sensor area 412 opposite the third side S3. Furthermore, the additional trench and the further additional trench do not form a continuous trench. In some examples, the number of additional trenches on one side may differ from the number of additional trenches on another side. For example, as in . Fig. As shown in 7B below, there are two additional trenches on the first side S1 and one additional trench on the fourth side S4.

[0031] Fig. Figure 5 shows a circuit diagram of an exemplary electronic system 550 configured to detect the current and temperature of a semiconductor device 500. The electronic system 550 can be part of a power electronics system, such as a DC / DC converter, an AC / DC converter, a DC / AC inverter, an AC / AC converter, etc.

[0032] The semiconductor device 500 is part of the electronic system 550 and comprises a main transistor 552, a current sensor transistor 554, and a temperature sensor device 556. The main transistor 552, the current sensor transistor 554, and the temperature sensor device 556 form an integrated circuit that is monolithically integrated into the semiconductor device 500. The semiconductor device 500 can be referred to as a semiconductor die. A collector region of the main transistor 552 and a collector region of the current sensor transistor 554 are both electrically connected to a collector terminal 558 of the semiconductor device 500. Gate electrodes of the main transistor 552 and gate electrodes of the current sensor transistor 554 are all electrically connected to a gate terminal 560 of the semiconductor device 500.A source region of the main transistor 552 is electrically connected to an emitter terminal 562 of the semiconductor device 500, and a source region of the current sensor transistor 554 is electrically connected to a sensor terminal 564 of the semiconductor device 500. The temperature sensor device 556 is electrically connected between the sensor terminal 564 and the emitter terminal 562. This means that a first terminal of the temperature sensor device 556 is electrically connected to the sensor terminal 564, and a second terminal of the temperature sensor device 556 is electrically connected to the emitter terminal 562.

[0033] The main transistor 552 may include an active device region similar to or identical to an active device region 108, 208, 308, or 408 described above. The current sensor transistor 554 may include a current sensor region similar to or identical to a current sensor region 112, 212, 312, or 412 described above. The current sensor transistor 554 reflects a current flowing in the main transistor 552, and a current flowing through the current sensor transistor 554 can be used to detect the current flowing through the main transistor 552, as described in more detail below. A transition region, comprising at least one additional trench, is arranged between the active device region and the current sensor region, as described above.The transition area may be similar or identical to a transition area 116, 216, 316, 416 explained above, and the at least one additional trench may be similar or identical to an additional trench 120, 220, 320, 348, 420 explained above.

[0034] In one example, the temperature sensor device 556 comprises at least one diode configured to detect the temperature of the semiconductor device 500, as described in more detail below. An anode terminal of the at least one diode is electrically connected to the sensor terminal 564, and a cathode terminal of the at least one diode is electrically connected to the emitter terminal 562. In another example, the temperature sensor device 556 comprises a plurality of diodes connected in series. The plurality of series-connected diodes can be referred to as a diode stack. In another example, an antiparallel diode can be connected between the sensor terminal 564 and the emitter terminal 562 to protect the main transistor 552 and the semiconductor device 500 from damage in the event of ESD (electrostatic discharge).The implementation of diodes to detect the temperature of semiconductor device 500 is just one example. In other examples, other semiconductor devices, such as a resistor, can be implemented to detect the temperature of semiconductor device 500.

[0035] In addition to the semiconductor device 500, the electronic system 550 comprises further circuit elements configured to sense the current and temperature of the semiconductor device 500. The electronic system 550 includes a switching device 566 and a current-sensing resistor 568 connected in series between the sensor terminal 564 and the emitter terminal 562. In one example, the switching device 566 includes a transistor. In another example, the switching device 566 can be controlled by the same signal 572 as the gate terminal 560 of the semiconductor device 500. Furthermore, the electronic system 550 includes a current source 570 connected between the sensor terminal 564 and the emitter terminal 562. The further circuit elements configured to sense the current and temperature of the semiconductor device 500 are provided as an example.Other examples may contain different and / or additional circuit elements.

[0036] In a first operating mode, the gate terminal 560 of the semiconductor device 500 and the switching device 566 are switched to a first state. For example, the first state can be an on state in which a high or positive voltage can be applied to the gate terminal 560 and in which the main transistor 552 and the current sensor transistor 554 are conducting. Furthermore, in the first state, the switching device 566 is conducting and couples the sensor terminal 564 of the semiconductor device 500 to the current sensing resistor 568. In the first operating mode, a current flowing through the current sensor transistor 554 is detected by sensing a voltage drop across the current sensing resistor 568, as measured between the sensor terminal 564 and the emitter terminal 562. The voltage can be detected at a time when the main transistor 552 and the current sensor transistor 554 are in a safe on state.The current flowing through the main transistor 552 can be determined based on the current flowing through the current sensor transistor 554 and the ratio of the main transistor 552's value to the current sensor transistor 554's value. In the first operating mode, the semiconductor device 500 is configured to allow a current measurement in the current sensor transistor 554, and this first operating mode can be referred to as the current sensing mode.

[0037] In a second operating mode, the gate terminal 560 of the semiconductor device 500 and the switching device 566 are switched to a second state. For example, the second state can be an off state in which a low, zero, or negative voltage can be applied to the gate terminal 560 and in which the main transistor 552 and the current sensor transistor 554 are non-conducting. Furthermore, in the second state, the switching device 566 is non-conducting and decouples the sensor terminal 564 of the semiconductor device 500 from the current sensing resistor 568. In the second operating mode, the current source 570 provides a constant current that flows through the temperature sensor device 556 of the semiconductor device 500.The second configuration allows temperature sensing of the semiconductor device 500 by detecting a voltage drop across the temperature sensor device 556, as measured between the sensor terminal 564 and the emitter terminal 562. The voltage drop can be detected at a time when the main transistor 552 and the current sensor transistor 554 are in a safe off state. In the second operating mode, the semiconductor device 500 is configured to allow temperature measurement of the semiconductor device 500, and the second operating mode can be referred to as the temperature sensing mode.

[0038] In the exemplary electronic system 550, as in Fig. As shown in Figure 5, a single terminal of the semiconductor device 500, which is the sensor terminal 564, is used for both current and temperature measurement. Thus, the sensor terminal 564 can be referred to as a dual-mode sensor terminal. Switching between current and temperature measurement is accomplished via the signal 572. A current is measured using the sensor terminal 564 when the gate terminal 560 is switched to a first state, and a temperature is measured using the sensor terminal 564 when the gate terminal 560 is switched to a second state.

[0039] Fig. Figure 6 shows a top view of a layout for an exemplary semiconductor device 600. The semiconductor device 600 may be similar to or identical with the semiconductor device 500, which is described in conjunction with Fig. Figure 5 illustrates and describes the following. A gate terminal of the semiconductor device 600 is electrically connected to a gate pad G, an emitter terminal of the semiconductor device 600 is electrically connected to an emitter pad E, and a sensor terminal of the semiconductor device 600 is electrically connected to a sensor pad S. The semiconductor device 600 is a vertical device, and the gate pad G, the emitter pad E, and the sensor pad S are arranged over a first major surface of a substrate of the semiconductor device 600. The collector terminal is electrically connected to a collector pad arranged over a second major surface of the substrate, which is opposite the first major surface. Thus, the collector pad is located in Fig. 6 out of sight.

[0040] The semiconductor device 600 comprises a temperature sensor area 674, which includes semiconductor devices that form a temperature sensor device of the semiconductor device 600. The semiconductor device 600 further comprises a current sensor area 612, which includes current sensor transistor cells that form a current sensor transistor of the semiconductor device 600. The semiconductor device 600 further comprises an active device area that is located at least partially beneath the emitter pad E. The active device area comprises power transistor cells that form a power transistor of the semiconductor device 600. A transition area, which includes at least one additional trench, is arranged between the active device area and the current sensor area, as explained above.

[0041] The in Fig. Layout 6 shown is only an example. In other examples, the temperature sensor area 674 may be located in different positions than those shown. Fig. 6 are located. For example, the temperature sensor area 674 may be located in or near the center of the semiconductor device 600, or the temperature sensor area 674 may be distributed over the semiconductor device 600. Similarly, the current sensor area 612, the gate pad G, the emitter pad E, and / or the sensor pad S may be located in positions other than those shown in Figure 6. Fig. The 6 shown are located. In one example, the emitter pad E can be divided into two or more emitter pads.

[0042] Sensor pad S is used for both current and temperature measurement of the semiconductor device 600. Switching between current and temperature measurement is accomplished via gate pad G. Using sensor pad S for both current and temperature measurement minimizes the effort required to access the pads, for example, during bonding, and also allows for high utilization of the active area. Furthermore, an electrode formed in the additional trench of the transition area suppresses or reduces leakage current flowing from the active device area to the current sensor area, or vice versa, as explained above.

[0043] Fig. 7A + Fig. 7B, Fig. 7D + Fig. Figure 7E shows enlarged top views of a section of implementations of a semiconductor device 700, which is located in Fig. 6 is indicated by a circle. Fig. 7C shows a cross-sectional view of the semiconductor device 700 along the line with AA' in Fig. 7A + Fig. Line 7B represents the line.

[0044] The semiconductor device 700 comprises a semiconductor substrate 702. The semiconductor substrate 702 has a first main surface 704 and a second main surface 706 opposite the first main surface 704. The semiconductor device 700 further comprises an active device area 708 and a current sensor area 712. The active device area 708 comprises a plurality of gate grooves 710 formed on the first main surface 704 of the semiconductor substrate 702 and extending along a first direction y parallel to the first main surface 704 of the semiconductor substrate 702. The active device area 708 can be similar to an active device area 108, 208, 308, 408 described above. In contrast, the active device area 708 further comprises a plurality of emitter trenches 776 extending along the first direction y parallel to and between the gate trenches 710.The active device area 708 comprises power transistor cells that form a power transistor of the semiconductor device 700. The emitter trenches 776 comprise emitter electrodes that are electrically connected to source regions formed in the active device area 708.

[0045] The current sensing region 712 comprises a plurality of gate trenches 714 formed on the first main surface 704 of the semiconductor substrate 702 and extending along the first direction y. The current sensing region 712 can be similar to a current sensing region 112, 212, 312, 412 described above. In contrast, the current sensing region 712 further comprises a plurality of emitter trenches 778 extending along the first direction y parallel to and between the gate trenches 714. Furthermore, the current sensing region 712 comprises an intersecting gate trench 780 extending at least partially along a second direction x that is orthogonal to the first direction y. The intersecting gate trench 780 connects at least a subset of the plurality of gate trenches 714 of the current sensing region 712. The current sensor area 712 comprises current sensor transistor cells that form a current sensor transistor of the semiconductor device 700.The emitter trenches 778 comprise emitter electrodes electrically connected to source areas formed in the current sensor area 712.

[0046] The semiconductor device 700 further comprises a transition region 716, which is arranged between the active device region 708 and the current sensor region 712. The transition region 716 includes an additional trench 720 and a further additional trench 748, which are formed on the first main surface 704 of the semiconductor substrate 702. Body regions 736 are formed on both sides of the additional trench 720 and the further additional trench 748. The additional trench 720 and the further additional trench 748 separate the majority of gate trenches 710 of the active device area 708 from the majority of gate trenches 714 of the current sensor area 712. The transition area 716 may be similar to or identical with a transition area 116, 216, 316, 416 described above, and the additional trench 720 and the further additional trench 748 may be similar to or identical with an additional trench 120, 220, 320, 348, 420 described above.The additional trench 720 and the further additional trench 748 extend at least partially along the second direction x and comprise electrodes that are not electrically connected to a plurality of gate electrodes formed in the gate trenches 710 of the active device area 708. Additionally, the electrodes formed in the additional trench 720 and the further additional trench 748 are not electrically connected to a plurality of gate electrodes formed in the gate trenches 714 of the current sensor area 712. In one example, the electrodes formed in the additional trench 720 and the further additional trench 748 are electrically connected to the source areas formed in the active device area 708. As in . Fig. As shown in Figure 7A, the additional trench 720 and the further additional trench 748 can be connected to at least one of the plurality of emitter trenches 776 of the active device area 708. Alternatively, as shown in Fig. As shown in Figure 7B, the additional trench 720 and the further additional trench 748 are not connected to at least one of the plurality of emitter trenches 776 of the active device area 708. In the example of Fig. 7B The electrodes formed in the additional trench 720 and the further additional trench 748 can be electrically connected to the source regions formed in the active device region 708 by means of a conductive layer formed above the semiconductor substrate 702 similar to that in Fig. The first conductive layer 742, as shown in Figure 7C, is connected. The implementation of the electrodes formed in the additional trench 720 and the further additional trench 748 enables a reduction or suppression of a leakage current, as previously described.

[0047] As shown in the cross-sectional view of Fig. As shown in Figure 7C, a first conductive layer 742 is formed over the first main surface 704 of the semiconductor substrate 702. The first conductive layer 742 can be similar to or identical to a first conductive layer 142 described above. The majority of gate electrodes of the active device region 708 are electrically connected to the majority of gate electrodes of the current sensor region 712 through the conductive layer 742 formed over the semiconductor substrate 702. The first conductive layer 742 can be segmented, and a segment of the conductive layer 742 can contact both the majority of gate electrodes of the active device region 708 and the majority of gate electrodes of the current sensor region 712.The segment of the conductive layer 742 can be electrically isolated from the electrodes formed in the additional trench 720 and the further additional trench 748 by a segmented dielectric intermediate layer 744 formed over the first main surface 704 of the semiconductor substrate 702. In one example, the segment of the conductive layer 742 can occupy only a portion of the transition region 716 located between the active device region 708 and the current sensor region 712.

[0048] Alternatively or additionally, as in Fig. As shown in Figure 7D, at least one 782 of the plurality of gate trenches 710 of the active device area 708 is connected to the intersecting gate trench 780 of the current sensor area 712. Thus, the plurality of gate electrodes formed in the gate trenches 710 of the active device area 708 are electrically connected to the plurality of gate electrodes formed in the gate trenches 714 of the current sensor area 712 via the at least one 782 of the plurality of gate trenches 710 of the active device area 708. There is no additional trench 720 and no further additional trench 748 in an area where the at least one 782 of the plurality of gate trenches 710 of the active device area 708 is connected to the intersecting gate trench 780.

[0049] The semiconductor device 700 from Fig. 7E is the semiconductor device 700 from Fig. 7D is similar. However, in the semiconductor device 700, it differs. Fig. 7D, the at least one 782 of the plurality of gate trenches 710 of the active device area 708, divides the transition area 716 into a first section 716_1 of the transition area 716 and a further section 716_2 of the transition area 716. This means that the transition area 716 and the additional trenches 720, 728 are locally interrupted to allow gate signaling.

[0050] In one example, the majority of emitter trenches 776 of the active device area 708 have the same width and / or depth as the majority of emitter trenches 778 of the current sensor area 712. In another example, the additional trench 720 and the further additional trench 748 have the same width and / or depth as the majority of emitter trenches 776 of the active device area 708 or the majority of emitter trenches 778 of the current sensor area 712. In another example, the intersecting gate trench 780 has the same width and / or depth as the majority of gate trenches 710 of the active device area 708 or the majority of gate trenches 714 of the current sensor area 712. By using trenches that have the same width and / or depth, a regular structure can be achieved and the manufacturing costs of the semiconductor device 700 can be reduced.

[0051] The in Fig. 7A- Fig. The semiconductor device 700 shown in Figure 7E is only one example. In other examples, at least a subset of the plurality of gate electrodes of the current sensor region 712 is connected by a conductive layer formed over the semiconductor substrate 702, similar to the first conductive layer 742 shown in Figure 7E. Fig. 7C is shown, electrically connected to each other. In this example, there can be no crossing gate trench 780 in the current sensor area 712. In one example, at least a subset of the plurality of gate electrodes of the active device area 708 is connected by a conductive layer similar to the first conductive layer 742 shown in Fig. 7C is depicted, and / or by a crossing gate trench similar to the crossing gate trench 780, which is shown in Fig.The components shown in Figure 7A are electrically connected. In one example, additional trenches may extend along the first direction y parallel to and between the gate trenches 710 of the active device area 708 and / or between the gate trenches 714 of the current sensor area 712. These additional trenches may include electrodes configured to be floating. The additional trenches may be referred to as dummy trenches. In one example, the transition area 716 includes at least one additional trench 720.

[0052] Examples of the present invention are summarized here. Other examples can also be understood from the entirety of the description and the claims filed herein.

[0053] Example 1: A semiconductor device comprising: a semiconductor substrate; an active device region comprising a plurality of gate grooves formed on a first principal surface of the semiconductor substrate; a current sensor region comprising a plurality of gate grooves formed on the first principal surface of the semiconductor substrate;and a transition region arranged between the active device region and the current sensing region, wherein the transition region comprises an additional trench formed on the first main surface of the semiconductor substrate, and wherein the additional trench separates the plurality of gate trenches of the active device region from the plurality of gate trenches of the current sensing region, and wherein an electrode formed in the additional trench is neither electrically connected to gate electrodes formed in the plurality of gate trenches of the active device region nor electrically connected to gate electrodes formed in the plurality of gate trenches of the current sensing region.

[0054] Example 2: The semiconductor device of Example 1, further comprising: an emitter / source pad formed over the semiconductor substrate and electrically connected to a source region formed in the active device region; a sensor pad formed over the semiconductor substrate and electrically connected to a source region formed in the current sensor region; and a gate pad formed over the semiconductor substrate and electrically connected to the plurality of gate electrodes of the active device region and to the plurality of gate electrodes of the current sensor region.

[0055] Example 3: The semiconductor device of Example 2, wherein the electrode formed in the additional trench is electrically connected to the source region of the active device region.

[0056] Example 4: The semiconductor device of one of Examples 2 or 3, further comprising: a temperature sensor area comprising a temperature sensor device, wherein a first terminal of the temperature sensor device is electrically connected to the sensor pad.

[0057] Example 5: The semiconductor device of Example 4, wherein the semiconductor device is configured to allow a measurement of a current in the current sensor area using the sensor pad when the gate pad is switched to a first state, and wherein the semiconductor device is further configured to allow a measurement of a temperature of the semiconductor device using the sensor pad when the gate pad is switched to a second state.

[0058] Example 6: The semiconductor device from Example 5, wherein the first state is an on-state and the second state is an off-state.

[0059] Example 7: The semiconductor device of one of Examples 4 to 6, wherein a second terminal of the temperature sensor device is electrically connected to the emitter / source pad.

[0060] Example 8: The semiconductor device of one of Examples 4 to 7, wherein the temperature sensor device comprises a plurality of diodes connected in series.

[0061] Example 9: The semiconductor device of one of the preceding examples, further comprising: a further additional trench extending parallel to the additional trench.

[0062] Example 10: The semiconductor device from one of the previous examples, wherein the additional trench at least partially surrounds the current sensor area.

[0063] Example 11: The semiconductor device from one of the preceding examples, wherein the current sensing region is embedded in the active device region, the additional trench separates the plurality of gate trenches of the active device region from the plurality of gate trenches of the current sensing region on a first side of the current sensing region, and another additional trench separates the plurality of gate trenches of the current sensing region from a plurality of further gate trenches of the active device region on a second side of the current sensing region opposite the first side.

[0064] Example 12: The semiconductor device from one of the preceding examples, wherein the majority of gate trenches of the active device area have the same width and / or depth as the majority of gate trenches of the current sensor area.

[0065] Example 13: The semiconductor device of one of the preceding examples, wherein the plurality of gate trenches of the active device region extends along a first direction parallel to the first principal surface of the semiconductor substrate, the active device region further comprising a plurality of emitter trenches extending along the first direction parallel to and between the gate trenches, the plurality of gate trenches of the current sensing region extending along the first direction parallel to the first principal surface of the semiconductor substrate, the current sensing region further comprising a plurality of emitter trenches extending along the first direction parallel to and between the gate trenches, and the additional trench extending at least partially along a second direction orthogonal to the first direction.

[0066] Example 14: The semiconductor device of Example 13, wherein the majority of emitter trenches of the active device area have the same width and / or depth as the majority of emitter trenches of the current sensor area.

[0067] Example 15: The semiconductor device of one of Examples 13 or 14, wherein the additional trench has the same width and / or depth as the majority of emitter trenches of the active device area or the majority of emitter trenches of the current sensor area.

[0068] Example 16: The semiconductor device of any of Examples 13 to 15, further comprising a crossing gate trench extending at least partially along the second direction and connecting at least a subset of the plurality of gate trenches of the current sensor area.

[0069] Example 17: The semiconductor device of Example 16, wherein the crossing gate trench has the same width and / or depth as the majority of gate trenches of the active device area or the majority of gate trenches of the current sensor area.

[0070] Example 18: The semiconductor device of one of Examples 16 or 17, wherein at least one of the plurality of gate trenches of the active device area is connected to the crossing gate trench.

[0071] Example 19: The semiconductor device of one of Examples 16 or 17, wherein the plurality of gate electrodes of the active device region are electrically connected to the plurality of gate electrodes of the current sensor region by a conductive layer formed over the semiconductor substrate.

[0072] Example 20: The semiconductor device of one of Examples 13 to 15, wherein at least a subset of the plurality of gate electrodes of the current sensor area are electrically interconnected by a conductive layer formed over the semiconductor substrate.

[0073] While this invention has been described with reference to illustrative examples, this description is not intended to be restrictive. Various modifications and combinations of the illustrative examples, as well as other examples of the invention, will be apparent to those skilled in the field upon reference to the description. It is therefore intended that the appended claims include any such modifications or examples.

Claims

[1] A semiconductor device (100, 200, 300, 400, 500, 600, 700) comprising: a semiconductor substrate (102, 702); an active device region (108, 208, 308, 408, 708) comprising a plurality of gate trenches (110, 210, 710) formed on a first main surface (104, 704) of the semiconductor substrate (102, 702); a current sensor region (112, 212, 312, 412, 612, 712) comprising a plurality of gate trenches (114, 214, 714) formed on the first main surface (104, 704) of the semiconductor substrate (102, 702); and a transition region (116, 216, 316, 416, 716) disposed between the active device region (108, 208, 308, 408, 708) and the current sensor region (112, 212, 312, 412, 612, 712), wherein the transition region (116, 216, 316, 416, 716) comprises an additional trench (120, 220, 320, 420, 720) formed on the first main surface (104, 704) of the semiconductor substrate (102, 702), and wherein the additional trench (120, 220, 320, 420, 720) separates the plurality of gate trenches (110, 210, 710) of the active device region (108, 208, 308, 408, 708) from the plurality of gate trenches (114, 214, 714) of the current sensor region (112, 212, 312, 412, 612, 712), and wherein an electrode (130) formed in the additional trench (120, 220, 320, 420, 720) is neither electrically connected to gate electrodes (126) formed in the plurality of gate trenches (110, 210, 710) of the active device region (108, 208, 308, 408, 708) nor electrically connected to gate electrodes (122) formed in the plurality of gate trenches (114, 214, 714) of the current sensor region (112, 212, 312, 412, 612, 712). [2] The semiconductor device (100, 200, 300, 400, 500, 600, 700) according to claim 1, further comprising: an emitter / source pad (E) formed over the semiconductor substrate (102, 702) and electrically connected to a source region formed in the active device region (108, 208, 308, 408, 708); a sensor pad (S) formed over the semiconductor substrate (102, 702) and electrically connected to a source region (134) formed in the current sensor region (112, 212, 312, 412, 612, 712); and a gate pad (G) formed over the semiconductor substrate (102, 702) and electrically connected to the plurality of gate electrodes (126) of the active device region (108, 208, 308, 408, 708) and to the plurality of gate electrodes (122) of the current sensor region (112, 212, 312, 412, 612, 712). [3] The semiconductor device (100, 200, 300, 400, 500, 600, 700) according to claim 2, wherein the electrode (130) formed in the additional trench (120, 220, 320, 420, 720) is electrically connected to the source region of the active device region (108, 208, 308, 408, 708). [4] A semiconductor device (500, 600) according to any one of claims 2 or 3, further comprising: a temperature sensor region (674) comprising a temperature sensor device (556), wherein a first terminal of the temperature sensor device (556) is electrically connected to the sensor pad (S). [5] The semiconductor device (500, 600) according to claim 4, wherein the semiconductor device (100, 200, 300, 400, 500, 600, 700) is configured to enable measurement of a current in the current sensor region (112, 212, 312, 412, 612, 712) using the sensor pad (S) when the gate pad (G) is switched to a first state, and wherein the semiconductor device (100, 200, 300, 400, 500, 600, 700) is further configured to enable measurement of a temperature of the semiconductor device (100, 200, 300, 400, 500, 600, 700) using the sensor pad (S) when the gate pad (G) is switched to a second state is switched. [6] The semiconductor device (500, 600) according to claim 5, wherein the first state is an on state and the second state is an off state. [7] The semiconductor device (500, 600) according to any one of claims 4 to 6, wherein a second terminal of the temperature sensor device (556) is electrically connected to the emitter / source pad (E). [8] The semiconductor device (500, 600) according to any one of claims 4 to 7, wherein the temperature sensor device (556) comprises a plurality of series-connected diodes. [9] Semiconductor device (300) according to one of the preceding claims, further comprising: a further additional trench (348, 748) extending parallel to the additional trench (320). [10] Semiconductor device (400) according to one of the preceding claims, wherein the additional trench (420) at least partially surrounds the current sensor region (412). [11] Semiconductor device (100, 200, 300, 400, 500, 600, 700) according to one of the preceding claims, wherein the current sensor region (112, 212, 312, 412, 612, 712) is embedded in the active device region (108, 208, 308, 408, 708), the additional trench (120, 220, 320, 420, 720) separates the plurality of gate trenches (110, 210, 710) of the active device region (108, 208, 308, 408, 708) from the plurality of gate trenches (114, 214, 714) of the current sensor region (112, 212, 312, 412, 612, 712) on a first side (S1) of the current sensor region (112, 212, 312, 412, 612, 712), and a further additional trench separates the plurality of gate trenches (114, 214, 714) of the current sensor region (112, 212, 312, 412, 612, 712) from a plurality of further gate trenches (110, 210, 710) of the active device region (108, 208, 308, 408, 708) on a second side (S2) of the current sensor region (112, 212, 312, 412, 612, 712) opposite the first side (S1). [12] Semiconductor device (100, 200, 300, 400, 500, 600, 700) according to one of the preceding claims, wherein the plurality of gate trenches (110, 210, 710) of the active device region (108, 208, 308, 408, 708) have a same width and / or a same depth as the plurality of gate trenches (114, 214, 714) of the current sensor region (112, 212, 312, 412, 612, 712). [13] Semiconductor device (700) according to one of the preceding claims, wherein the plurality of gate trenches (710) of the active device region (708) extend along a first direction (y) parallel to the first main surface (704) of the semiconductor substrate (702), the active device region (708) further comprises a plurality of emitter trenches (776) extending along the first direction (y) parallel to and between the gate trenches (710), the plurality of gate trenches (714) of the current sensor region (712) extend along the first direction (y) parallel to the first main surface (704) of the semiconductor substrate (702), the current sensor region (712) further comprises a plurality of emitter trenches (778) extending along the first direction (y) parallel to and between the gate trenches (714), and the additional trench (720) extends at least partially along a second direction (x) which is orthogonal to the first direction (y). [14] The semiconductor device (700) of claim 13, wherein the plurality of emitter trenches (776) of the active device region (708) have a same width and / or a same depth as the plurality of emitter trenches (778) of the current sensor region (712). [15] The semiconductor device (700) according to any one of claims 13 or 14, wherein the additional trench (720) has a same width and / or a same depth as the plurality of emitter trenches (776) of the active device region (708) or the plurality of emitter trenches (778) of the current sensor region (712). [16] A semiconductor device (700) according to any one of claims 13 to 15, further comprising: a crossing gate trench (780) extending at least partially along the second direction (x) and interconnecting at least a subset of the plurality of gate trenches (714) of the current sensor region (112, 212, 312, 412, 612, 712). [17] The semiconductor device (700) of claim 16, wherein the crossing gate trench (780) has a same width and / or a same depth as the plurality of gate trenches (710) of the active device region (708) or the plurality of gate trenches (714) of the current sensor region (712). [18] The semiconductor device (700) of claim 16 or 17, wherein at least one (782) of the plurality of gate trenches (710) of the active device region (708) is connected to the crossing gate trench (780). [19] The semiconductor device (700) according to any one of claims 16 or 17, wherein the plurality of gate electrodes of the active device region (708) are electrically connected to the plurality of gate electrodes of the current sensor region (712) through a conductive layer (742) formed over the semiconductor substrate (702). [20] The semiconductor device (700) according to any one of claims 13 to 15, wherein at least a subset of the plurality of gate electrodes of the current sensor region (712) are electrically connected to each other by a conductive layer formed over the semiconductor substrate (702).

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