DE102016218821A1 - Semiconductor component, semiconductor power module for a motor vehicle and motor vehicle - Google Patents

Abstract

Semiconductor component, comprising a substrate (18) of a semiconductor material, in which substrate (18) semiconductor junctions of a transistor structure (22) of the semiconductor device (17) are formed, wherein within the substrate (18) a substrate (18) in two substrate sections (20 , 21), the semiconductor junctions of the first transistor structure (22) in a substrate portion (20) and semiconductor junctions of a second transistor structure (35) of the semiconductor device (17) in the other substrate portion (21) are formed ,

Description

The invention relates to a semiconductor component, comprising a substrate made of a semiconductor material, in which substrate semiconductor junctions of a transistor structure of the semiconductor component are formed.

Such semiconductor devices are used in the field of power electronics for switching purposes. In this case, the transistor structure typically forms a power MOSFET or an IGBT, which can be driven via its gate for controlling a current flow between a collector and an emitter connection or between a drain and a source connection. For the construction of circuits with multiple transistors typically two discrete, so separate, semiconductor devices are used, in each of which a single transistor structure is realized.

So revealed DE 40 40 691 A1 a semiconductor device package having an electrically insulating ceramic substrate, three power terminals respectively connected to the substrate, the first and third external power terminals arranged opposite to the second external power terminal. The device is further adapted to receive two switching devices in the form of power MOSFETs of a half-bridge circuit.

From the use of semiconductor devices, which only realize a transistor structure, followed by a correspondingly high space requirement for semiconductor circuits in which a plurality of transistor structures are interconnected, since a plurality of semiconductor devices must be used.

The invention is therefore based on the object to reduce the space requirement of semiconductor circuits based on a semiconductor device.

This object is achieved in a semiconductor device of the type mentioned above in that within the substrate, a substrate dividing the substrate into two, electrically insulating separation layer is formed, wherein the semiconductor junctions of the first transistor structure in a substrate portion and semiconductor junctions of a second transistor structure of the semiconductor device in the other Substrate portion are formed.

The invention is based on the consideration of forming a plurality of transistor structures based on a single substrate, for example a wafer, wherein the transistor structures are separated from one another by an electrically insulating separating layer in order to reduce or avoid mutual influencing of their semiconductor structures. The semiconductor component can be considered monolithic in this respect. The semiconductor junctions, in particular between differently or differently doped zones, of a transistor structure are thus formed within a respective substrate section and separated from one another by the separating layer, which may be formed, for example, by doping, the introduction of an oxide layer or etching. The semiconductor component according to the invention thus makes it possible to realize a plurality of transistor structures in the semiconductor component based on a single substrate made of a semiconductor material, whereby the use of a plurality of semiconductor components and the associated high installation space requirement can be avoided when constructing semiconductor circuits with a plurality of transistor structures.

Preferably, the transistor structures are each formed as a bipolar transistor with insulated gate. Such a transistor structure, also referred to as an IGBT, is generally characterized in particular by npnp junctions in the case of an n-channel IGBT or by pnpn junctions in the case of a p-channel IGBT and by a gate structure electrically insulated from these semiconductor junctions Substrate section is arranged. Alternatively, the transistor structures may each be formed as an insulated gate field effect transistor. Such a transistor structure is also referred to as an IGFET and may be, for example, a metal-insulator-semiconductor field-effect transistor (MISFET), in particular a metal-oxide-semiconductor field-effect transistor (MOSFET). Again, the insulating gate structure may be disposed at the respective substrate portion forming the semiconductor junctions of the transistor structure. For both semiconductor structures, a multiplicity of design variants designed in particular for power electronics applications are known, which can in principle be used to form the semiconductor component according to the invention.

Furthermore, it is expedient if the transistor structures are each of the same channel type. Thus, in particular with regard to the realization of semiconductor circuits provided for switching purposes, a suitable configuration of the transistor structures in the semiconductor component can be selected.

In addition, in each case vertically formed transistor structures can be used in the semiconductor device according to the invention. The term "vertical" does not necessarily refer to the spatial orientation of the respective transistor structure, but to the fact that the semiconductor junctions of such a transistor structure are typically arranged such that a current flow through the transistor structure from one surface of the Subtratabschnitts to an opposite surface of the substrate section. Alternatively, the transistor structures may be formed laterally. In this case, a current flow through the semiconductor junctions typically takes place substantially along a surface of the substrate section.

Particularly preferably, a semiconductor electrode bridging the separating layer is formed on a surface of the substrate in the case of the semiconductor component according to the invention. The, in particular metallic, center electrode can thus establish a connection between the first transistor structure and the second transistor structure. Such a center electrode can be formed much shorter than a conventional connection between two discrete transistors due to the high degree of integration of the semiconductor device. In addition, this considerably reduces the commutation inductance when used in power electronics.

It is particularly expedient for the center electrode to be in contact with the first transistor structure on the collector or drain side and with the second transistor structure on the emitter or source side. The transistor structures can thus be connected in series by the center electrode, which is expedient for a realization of very different semiconductor circuits. In particular, the center electrode can serve as a tap of a potential lying between the transistor structures.

Furthermore, two electrically conductive outer electrodes may be provided, wherein a first outer electrode on the emitter or source side with the first transistor structure and the second outer electrode on the collector or drain side is contacted with the second transistor structure. The outer electrodes thus form an external connection possibility for interconnecting the semiconductor component, for example in a semiconductor power module. In this case, the collector or drain of the second transistor structure typically has a high potential (high side) and a low potential (low side) of the semiconductor circuits to be realized at the emitter or source of the first transistor structure. The outer electrodes are preferably arranged on a second surface, opposite the first surface, of the substrate forming the semiconductor junctions of the vertical transistor structures. In other words, the vertical transistor structures are rotated by 180 °. For example, gate structures of the transistor structures are arranged on different surfaces. Alternatively, the outer electrodes are arranged on the surface of the substrate forming the lateral transistor structures. Gate structures of the transistor structures can also be arranged on the same surface.

Particularly preferably, the semiconductor component implements a half-bridge circuit which can be controlled via a gate connection of a respective transistor structure and / or whose center tap is formed by the center electrode. Such a half-bridge circuit having two series-connected transistors is an essential basic circuit for a large number of electronic applications, in particular in the field of power electronics. Depending on the activation of the gate connections, the high-side potential, the low-side potential or a potential lying between these potentials can be tapped at the center tap. It is therefore possible to realize the half-bridge circuit by a single, monolithic semiconductor component, wherein the interconnection of the transistors of the half-bridge circuit can be realized solely by the center electrode arranged on the substrate.

In particular with regard to the power electronic use of the semiconductor component according to the invention, it is preferred if in the substrate sections in each case an antiparallel connected to the transistor structure diode structure is formed. By means of this diode structure, a freewheeling diode can be realized, which leads against the intended current direction through the transistor structures flowing currents, which flow, for example, from an inductive load in the semiconductor device to the sensitive transistor structures. It is thus achieved a further degree of integration and an additional space reduction by the semiconductor device. A diode structure can be contacted on the anode side with an outer electrode and the cathode side with the center electrode and the other diode structure on the anode side with the center electrode and the cathode side with the other outer electrode. Expediently, the diode structure implements a pin diode, that is to say a transition from a heavily p-doped zone via a weakly n-doped zone (so-called intrinsically conductive zone) to a heavily n-doped zone. In particular, in the case of vertical transistor structures, such a diode structure can be formed with little effort, in antiparallel to the transistor structure.

In addition, it is preferred in the case of the semiconductor component according to the invention if semiconductor junctions of a plurality of transistor structures are formed in a respective substrate section, which can each be contacted separately. In other words, in each case a plurality of transistor structures may be provided on both sides of the separation layer. In this case, all embodiments of the previously described pair comprising the first and the second transistor structure can be transferred to a respective further pair of further transistor structures separated by the separating layer. Thus, for example, a plurality of parallel-connected half-bridges can be implemented in monolithic fashion, for example for a polyphase inverter.

The object underlying the invention is further achieved by a semiconductor power module for a motor vehicle, comprising at least one semiconductor component according to the invention. The semiconductor power module may, for example, be part of a steering control device, a transmission control device or an electrically driven air conditioning compressor. Alternatively, the semiconductor power module may be or be part of an inverter or DC-DC converter.

In addition, the object underlying the invention is achieved by a motor vehicle comprising at least one inventive semiconductor power module.

All embodiments of the semiconductor device according to the invention can be analogously transferred to the semiconductor power module according to the invention and the motor vehicle according to the invention, so that even with these the advantages mentioned above can be achieved.

Further advantages and details of the invention will become apparent from the embodiments described below and with reference to the drawings. These are schematic representations and show:

1 a schematic diagram of a motor vehicle according to the invention;

2 a circuit diagram of a half-bridge circuit of a semiconductor power module according to the invention of the motor vehicle;

3 a layer representation of a first embodiment of a semiconductor device according to the invention; and

4 a layer representation of a second embodiment of a semiconductor device according to the invention.

1 shows a schematic diagram of a motor vehicle 1 comprising a semiconductor power module 2 which, for example, part of a steering control device, a transmission control device, an electrically driven air conditioning compressor, an inverter or a DC-DC converter of the motor vehicle 1 is. The semiconductor power module 2 has one or more half-bridge circuits 3 on.

2 shows a circuit diagram of the half-bridge circuit 3 , This includes a first transistor 4 and a second transistor 5 each in the form of a p-channel insulated gate bipolar transistor (IGBT) connected in series between one at a high potential 6 lying line and one at a low potential 7 lying line are interconnected. This is an emitter 8th of the first transistor 4 with the low potential 7 and a collector 9 of the first transistor 4 with an emitter 10 of the second transistor 5 connected. Its collector 11 again lies at the high potential 6 , Between the emitter 10 and the collector 9 is a middle tap 12 intended. By controlling a gate 13 of the first transistor 4 and a gate 14 of the second transistor 5 can be at the center tap 12 either the high potential 6 , the low potential 7 or pick up an intermediate potential.

Anti-parallel to the transistors 4 . 5 is each a diode 15 . 16 switched so that a current flow from the low potential 7 or from the center tap 12 in the direction of the high potential 6 at the transistors 4 . 5 is passed. Such a current flow can be achieved, for example, by an inductive load of the half-bridge circuit 3 be caused and the sensitive structures of the transistors 4 . 5 damage.

3 shows a layer representation of an embodiment of a semiconductor device 17 that is the half-bridge circuit 3 realized.

The semiconductor device 17 includes a substrate 18 from a semiconductor material. Within the substrate 18 is an electrically insulating separating layer 19 , For example, by doping, introducing an oxide layer or etching, which forms the substrate 18 in a first substrate section 20 and in a second substrate portion 21 divides.

Within the first substrate section 20 are both the semiconductor junctions of a first transistor structure 22 formed, to which further comprises a surface side on the first substrate portion 20 arranged isolated gate structure 23 as well as the semiconductor junctions of a diode structure 24 educated. The semiconductor junctions of the first transistor structure 22 are due to a weakly n-doped epitaxial growth zone 25 formed, in the two heavily p-doped tubs 26 . 27 each with a heavily n-doped island 28 . 29 are formed. The tubs 26 . 27 touch the isolated gate structure 23 partially. On the tubs 26 . 27 opposite side of the epitaxial zone 25 there is a heavily n-doped buffer zone 30 , in the region of the first transistor structure 22 a heavily p-doped zone 45 connects and located in the area of the first diode structure 24 up to a first surface 31 of the substrate 18 extends. The first substrate section 20 thus forms both the npnp junction of the first transistor structure 22 for the vertical IGBT as well as the pin junction of the first diode structure 24 out.

The first transistor structure 22 thus forms the first transistor 4 the in 2 shown half-bridge circuit 3 out. Its antiparallel diode is further characterized by the first diode structure 24 educated. At the first surface 31 opposite second surface 32 of the substrate 18 is an electrically conductive first outer electrode 33 provided the gate structure 23 borders and the emitter 8th with the anode of the diode 15 combines. At the first surface 31 is an electrically conductive center electrode 34 provided the collector 9 with the cathode of the diode 15 combines.

Within the second substrate section 21 are semiconductor junctions of a second transistor structure 35 and a second diode structure 36 formed, that of the first transistor structure 22 or the first diode structure 24 correspond, but with respect to one parallel to the surfaces 31 . 32 extending plane are arranged mirrored. Furthermore, a second gate structure 37 the second transistor structure 35 at the first surface 31 intended. Thus, form the second transistor structure 35 the second transistor 5 and the second diode structure 36 the second diode 16 the in 2 shown half-bridge circuit 3 out. To connect the collector 9 with the emitter 10 bridges the center electrode 34 the separation layer 19 and sums to the second substrate portion 21 the second gate structure 37 one. The center electrode 34 It also forms the connection of the cathode of the second diode 16 with the emitter 10 of the second transistor 5 , At the second surface 32 is in the region of the second substrate section 21 a second outer electrode 38 provided the collector 11 of the second transistor 5 with the anode of the second diode 16 combines.

Thus, the half-bridge circuit is 3 monolithic by means of a single substrate 18 formed semiconductor device 17 realized, wherein the first outer electrode 33 with the low potential 7 and the second outer electrode 38 with the high potential 6 to connect. The center tap 12 is through the center electrode 34 provided.

According to a further embodiment of the semiconductor device 17 are the transistor structures 22 . 35 as vertical field effect transistors with insulated gate (IGFET), for example as metal oxide semiconductor field effect transistors (MOSFET). Functionally, the emitters correspond 8th . 10 a respective source and the collectors 9 . 11 a respective drain of the IGFET.

4 shows a further embodiment of a semiconductor device 17 , whose transistor structures 22 . 35 in contrast to the previously described embodiment, each are formed as a lateral n-channel IGBT. Here are both the outer electrodes 33 . 38 as well as the center electrode 34 on the same surface 32 of the substrate 18 arranged.

The substrate 18 points to it in the first substrate section 20 a p-doped base zone 39 on, in the area of the emitter 8th of the first transistor 4 contacting first outer electrode 33 a heavily p-doped zone 40 and a heavily n-doped zone 41 is trained. Collector side is another heavily p-doped zone 42 formed in the vertical direction through an n-doped buffer zone 43 from the base zone 39 and in the lateral direction through an n-doped drift zone 44 from the base zone 39 is disconnected. The gate structure 23 the first transistor structure 22 is here at the surface 32 formed and adjacent in the vertical direction directly to the base zone 39 at.

In the second substrate section 21 are the semiconductor junctions of the second transistor structure 35 analogous to the first transistor structure 22 realized, with the gate structure 37 also on the surface 32 is trained. Again, the center electrode bridges 34 the separation layer 19 of the substrate 18 and thus establishes the connection between the collector 9 of the first transistor 4 and the emitter 10 of the second transistor 5 ago. The second outer electrode 38 accordingly contacts the collector 11 of the second transistor 5 for the formation of the half-bridge circuit 3 according to 2 ,

According to a further embodiment of the in 4 shown semiconductor device 17 are the transistor structures 22 . 35 as a lateral IGFET, for example as a MOSFET. Again, the emitters are the same 8th . 10 functionally a respective source connection and the collectors 9 . 11 a respective drain of the IGFET.

According to a further embodiment of the in the 3 and 4 shown semiconductor devices 17 are on both sides of the separation layer 19 in each case a plurality of transistor structures 22 . 35 and diode structures 24 . 36 formed so that several half-bridge circuits in parallel in the substrate 18 will be realized. The separating layer runs thereby 19 consistently between the substrate sections 20 . 21 in which respective semiconductor junctions of a plurality of first and second transistor structures 22 . 35 are formed.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 4040691 A1 [0003]

Claims (14)

Semiconductor device comprising a substrate ( 18 ) of a semiconductor material, in which substrate ( 18 ) Semiconductor junctions of a transistor structure ( 22 ) of the semiconductor device ( 17 ), characterized in that within the substrate ( 18 ) one the substrate ( 18 ) in two substrate sections ( 20 . 21 ) dividing, electrically insulating separating layer ( 19 ), wherein the semiconductor junctions of the first transistor structure ( 22 ) in a substrate section ( 20 ) and semiconductor junctions of a second transistor structure ( 35 ) of the semiconductor device ( 17 ) in the other substrate section ( 21 ) are formed. Semiconductor component according to Claim 1, characterized in that transistor structures ( 22 . 35 ) are each formed as an insulated gate bipolar transistor or as an insulated gate field effect transistor. Semiconductor component according to Claim 1 or 2, characterized in that the transistor structures ( 22 . 35 ) are each of the same channel type. Semiconductor component according to one of the preceding claims, characterized in that the transistor structures ( 22 . 35 ) are each formed vertically or laterally. Semiconductor component according to one of the preceding claims, characterized in that on a surface ( 31 ) of the substrate ( 18 ) one the separating layer ( 19 ) bridging electrically conductive center electrode ( 34 ) is trained. Semiconductor component according to Claim 5, characterized in that the center electrode ( 34 ) on the collector or drain side with the first transistor structure ( 22 ) and emitter or source side with the second transistor structure ( 34 ) is contacted. Semiconductor component according to claim 5 or 6, characterized in that two electrically conductive outer electrodes ( 33 . 38 ) are provided, wherein a first outer electrode ( 33 ) emitter or source side with the first transistor structure ( 32 ) and the second outer electrode ( 38 ) on the collector or drain side with the second transistor structure ( 35 ) is contacted. Semiconductor component according to Claims 4 and 7, characterized in that the external electrodes ( 33 . 38 ) on one of the first surfaces ( 31 ) opposite second surface ( 32 ) of which the semiconductor junctions of the vertical transistor structures ( 22 . 35 ) forming substrate ( 18 ) or on the surface ( 31 ) the semiconductor junctions of the lateral transistor structures ( 22 . 35 ) forming substrate ( 18 ) are arranged. Semiconductor component according to one of Claims 6 to 8, characterized in that it has a half-bridge circuit ( 3 ) realized via a gate terminal of a respective transistor structure ( 22 . 35 ) is controllable and / or whose center tap ( 12 ) through the center electrode ( 34 ) is trained. Semiconductor component according to one of the preceding claims, characterized in that in the substrate sections ( 20 . 21 ) each have an antiparallel to the transistor structure switched diode structure ( 24 . 36 ) is trained. Semiconductor component according to one of the preceding claims, characterized in that in a respective substrate section ( 20 . 21 ) Semiconductor junctions of several transistor structures ( 22 . 35 ) are formed, which are each separately contacted. Semiconductor power module for a motor vehicle ( 1 ) comprising at least one semiconductor device ( 17 ) according to any one of the preceding claims. Semiconductor power module according to claim 12, characterized in that it is part of a steering control device, a transmission control device or an electrically driven air conditioning compressor or is an inverter or a DC-DC converter or is part of such. Motor vehicle comprising at least one semiconductor power module ( 2 ) according to claim 12 or 13.

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