阅读说明：本技术 反向导通绝缘栅双极晶体管 (Reverse conducting insulated gate bipolar transistor ) 是由 F·D·普菲尔施 E·格里布尔 V·拉皮杜斯 A·毛德 C·P·桑多 A·韦莱 于 2021-03-17 设计创作，主要内容包括：公开了反向导通绝缘栅双极晶体管。一种RC IGBT(1),其在有源区(1-2)中包括IGBT区段(1-21)和至少三个二极管区段(1-22)。二极管区段(1-22)的布置服从一设计规则。(Reverse-conducting insulated gate bipolar transistors are disclosed. An RC IGBT (1) comprises an IGBT section (1-21) and at least three diode sections (1-22) in an active region (1-2). The arrangement of the diode sections (1-22) is subject to a design rule.)

1. An RC IGBT (1) comprising:

-an active region (1-2) having an IGBT section (1-21) and a plurality of at least three diode sections (1-22);

-an edge termination region (1-3) surrounding the active region (1-2);

-a semiconductor body (10) extending in both the active region (1-2) and the edge termination region (1-3) and having a front side (110) and a back side (120), the semiconductor body (10) having a thickness (d) which is the distance in a vertical direction (Z) from the front side (110) to the back side (120) in one of the diode sections (1-22);

-a first load terminal (11) and a control terminal (13), both at the front side (110) of the semiconductor body, and a second load terminal (12) at the back side (120) of the semiconductor body, wherein

Each diode section (1-22) is configured for conducting a diode load current between the first load terminal (11) and the second load terminal (12); and

the IGBT section (1-21) is configured for conducting a forward load current between the second load terminal (12) and the first load terminal (11);

the control terminal (13) is electrically connected to an electrically conductive control flow channel structure (131), the electrically conductive control flow channel structure (131) being arranged at the front side (110) of the semiconductor body and extending at least partially along the course of the lateral perimeter (1-20) of the active region (1-2),

-a plurality of control trenches (14) arranged parallel to each other along a first lateral direction (X) and extending into the semiconductor body (10) along a vertical direction (Z) pointing from the front side (110) to the back side (120), each control trench (14)

Having a strip-like configuration extending along a second transverse direction (Y) from respective first sections of the transverse perimeter (1-20) towards respective second sections of the transverse perimeter (1-20) opposite to the respective first sections, wherein the first transverse direction (X) is perpendicular to the second transverse direction (Y); and

accommodating an insulated control electrode (141), the insulated control electrode (141) being configured to receive a control signal via the control flow channel structure (131) for controlling the IGBT segments (1-21); wherein:

-each control trench (14) is interrupted no more than once by at most a single one of the diode sections (1-22) along its respective extension in the second lateral direction (Y);

-in the lateral region of the active region (1-2), the diode segments (1-22) do not overlap each other in a lateral direction themselves and the horizontal projections of the diode segments (1-22) do not overlap each other in a lateral direction along the second lateral direction (Y); and

-within a lateral region of the active region (1-2), horizontal projections along the first lateral direction (X) of the at least two diode sections (1-22) do not overlap each other.

2. The RC IGBT (1) according to claim 1, wherein no control trench (14) extends into one or more of the diode sections (1-22).

3. The RC IGBT (1) according to claim 1 or 2, wherein the IGBT sections (1-21) are continuous within the active region (1-2).

4. The RC IGBT (1) according to one of the preceding claims, wherein each diode section (1-22) is surrounded by a part of the IGBT section (1-21).

5. The RC IGBT (1) according to one of the preceding claims, wherein the lateral distance (xy1, xy2) between any one of the diode sections (1-22) and another one of the diode sections (1-22) or, respectively, between any one of the diode sections (1-22) and the edge termination region (1-3) at least amounts to the semiconductor body thickness (d).

6. The RC IGBT (1) according to one of the preceding claims, wherein each of the at least two diode sections (1-22) has a lateral extension along the first lateral direction (X) of at least five times the semiconductor body thickness (d).

7. The RC IGBT (1) according to claim 6, wherein each of the at least two diode sections (1-22) further has a lateral extension along the second lateral direction (Y) of at least five times the thickness (d) of the semiconductor body (10).

8. The RC IGBT (1) according to one of the preceding claims, wherein the total lateral area of the diode sections (1-22) forms a fraction of 5% to 40% of the total lateral area of both the diode sections (1-22) and the IGBT sections (1-21).

9. The RC IGBT (1) according to one of the preceding claims, wherein each diode section (1-22) has a lateral area and a perimeter defining the lateral area, wherein each diode section (1-22) obeys a relation of the square of the perimeter divided by the area being less than or equal to 20.

10. The RC IGBT (1) according to one of the preceding claims, wherein the control trench (14) is constituted by an uninterrupted control trench and a control trench interrupted once by a respective one of the diode sections (1-22), the control electrode (141) in the uninterrupted control trench extends continuously along the second lateral direction (Y), and the control electrode (141) in the interrupted control trench is divided into a first control electrode (1411) and a second control electrode (1412) as follows: the first control electrode (1411) is in a first control trench portion preceding the respective diode segment (1-22) with respect to the second lateral direction (Y); a second control electrode (1412) in a second control trench portion after the respective diode segment (1-22) with respect to a second lateral direction (Y), wherein:

-each of the control electrodes (141, 1411, 1412) in the interrupted and uninterrupted control trenches (14) is electrically connected at its respective two lateral ends to the potential of the control terminal (13) by means of a respective first conductive structure extending along the first lateral direction (X) and a respective second conductive structure extending along the first lateral direction (X).

11. The RC IGBT (1) according to claim 10, wherein for an uninterrupted control trench both the first and the second conductive structure are realized by means of a control flow channel structure (131).

12. The RC IGBT (1) according to claim 10 or 11, wherein for an interrupted control trench one of the first and second conductive structures is realized by means of a control flow channel structure (131) and the other of the first and second conductive structures is realized by means of a crossing trench structure (18), the crossing trench structure (18) being arranged near the diode section (1-22) and extending at least partially along the first lateral direction (X).

13. The RC IGBT (1) according to claim 12, wherein the intersecting trench structure (18) comprises intersecting trench electrodes (181), the intersecting trench electrodes (181) electrically connecting the first control electrodes (1411) of two adjacent interrupted control trenches (14) preceding the diode section (1-22).

14. The RC IGBT (1) of one of the preceding claims, further comprising a plurality of source trenches (16) at least in the IGBT sections (1-21), the plurality of source trenches (16) being arranged parallel to each other along the first lateral direction (X) and extending into the semiconductor body (10) along the vertical direction (Z), each source trench (16)

-having a strip-like configuration extending along a second transverse direction (Y) from a respective first section of the transverse perimeter (1-20) towards a respective second section of the transverse perimeter (1-20) opposite to the respective first section; and

-an insulated source electrode (161) containing an electrical potential electrically connected to the first load terminal (11).

15. The RC IGBT (1) according to claim 12 or 13 and 14, wherein at least one of the source trenches (16) is interrupted by one of the diode regions (1-22), the source trench (16) being arranged between two interrupted control trenches (14), the intersection trench structure (18) being moved away from the end of the source trench (16) along the second lateral direction (Y).

16. The RC IGBT (1) according to claim 14 or 15, wherein no source trench (16) extends into one or more of the diode regions (1-22), and/or wherein each source trench (16) is interrupted no more than once by at most a single one of the diode regions (1-22) along its respective extension in the second lateral direction (Y).

17. The RC IGBT (1) according to claim 14 or 15, wherein one or more of the source trenches (16) extend into one or more of the diode regions (1-22).

18. The RC IGBT (1) according to one of the preceding claims, wherein each diode section (1-22) is separated from the IGBT section (1-21) by means of a substantially continuous structure (15) electrically connected to the potential of the first load terminal (11).

19. The RC IGBT (1) according to one of the preceding claims, wherein each diode region (1-22) is laterally displaced from any semiconductor region (101) of the first conductivity type which is electrically connected to the first load terminal (11) by a distance (dxy) of at least 5 μ ι η.

20. A method of processing an RC IGBT (1), comprising forming the following components of the RC IGBT (1):

-an active region (1-2) having an IGBT section (1-21) and a plurality of at least three diode sections (1-22);

-an edge termination region (1-3) surrounding the active region (1-2);

-a semiconductor body (10) extending in both the active region (1-2) and the edge termination region (1-3) and having a front side (110) and a back side (120), the semiconductor body (10) having a thickness (d) which is the distance in a vertical direction (Z) from the front side (110) to the back side (120) in one of the diode sections (1-22);

-a first load terminal (11) and a control terminal (13), both at the front side (110) of the semiconductor body, and a second load terminal (12) at the back side (120) of the semiconductor body, wherein

Each diode section (1-22) is configured for conducting a diode load current between the first load terminal (11) and the second load terminal (12); and

the IGBT section (1-21) is configured for conducting a forward load current between the second load terminal (12) and the first load terminal (11);

the control terminal (13) is electrically connected to an electrically conductive control flow channel structure (131), the electrically conductive control flow channel structure (131) being arranged at the front side (110) of the semiconductor body and extending at least partially along the course of the lateral perimeter (1-20) of the active region (1-2),

-a plurality of control trenches (14) arranged parallel to each other along a first lateral direction (X) and extending into the semiconductor body (10) along a vertical direction (Z) pointing from the front side (110) to the back side (120), each control trench (14)

Having a strip-like configuration extending along a second transverse direction (Y) from respective first sections of the transverse perimeter (1-20) towards respective second sections of the transverse perimeter (1-20) opposite to the respective first sections, wherein the first transverse direction (X) is perpendicular to the second transverse direction (Y); and

accommodating an insulated control electrode (141), the insulated control electrode (141) being configured to receive a control signal via the control flow channel structure (131) for controlling the IGBT segments (1-21);

wherein the processing method comprises, subject to a design rule, according to which:

-each control trench (14) is interrupted no more than once by at most a single one of the diode sections (1-22) along its respective extension in the second lateral direction (Y);

-in the lateral region of the active region (1-2), the diode segments (1-22) do not overlap each other in a lateral direction themselves and the horizontal projections of the diode segments (1-22) do not overlap each other in a lateral direction along the second lateral direction (Y); and

-within a lateral region of the active region (1-2), horizontal projections along the first lateral direction (X) of the at least two diode sections (1-22) do not overlap each other.

Technical Field

The present description relates to embodiments of a power semiconductor device and embodiments of a method of processing a power semiconductor device. In particular, the present description relates to embodiments of a reverse-conducting insulated gate bipolar transistor (RC IGBT), wherein several diode sections of the RC IGBT are arranged in an active region according to design rules, and to embodiments of a corresponding processing method.

Background

Many functions of modern equipment in automotive, consumer and industrial applications, such as converting electrical energy and driving electric motors or machines, rely on power semiconductor switches. For example, Insulated Gate Bipolar Transistors (IGBTs), Metal Oxide Semiconductor Field Effect Transistors (MOSFETs), and diodes have been used in a variety of applications, including but not limited to power supplies and switches in power converters, to name a few.

Power semiconductor devices typically include a semiconductor body configured to conduct a forward load current along a load current path between two load terminals of the device.

Further, in the case of a controllable power semiconductor device (e.g. a transistor), the load current path may be controlled by means of an insulated electrode, usually called gate electrode. For example, the control electrode may set the power semiconductor device in one of a forward conducting state and a blocking state when receiving a corresponding control signal from, for example, a driver unit. In some cases, the gate electrode may be included within a trench of the power semiconductor switch, wherein the trench may assume, for example, a stripe-like configuration or a needle-like configuration.

Some power semiconductor devices further provide reverse conductivity; during the reverse conducting state, the power semiconductor device conducts a reverse load current. Such a device may be designed such that the forward load current capability (in terms of magnitude) is substantially the same as the reverse load current capability.

A typical device that provides forward and reverse load current capability is a Reverse Conducting (RC) IGBT, the general configuration of which is known to those skilled in the art. Typically, for an RC IGBT, the forward conduction state is controllable by means of providing a corresponding signal to the gate electrode, and the reverse conduction state is typically not controllable, but the RC IGBT assumes the reverse conduction state if a reverse voltage is present at the load terminals due to one or more diode structures in the RC IGBT.

Of course the reverse current capability can be provided by means of a separate diode; for example a diode connected in anti-parallel to a conventional (non-reverse conducting) IGBT. However, the embodiments described herein relate to a variant in which both the IGBT structure and the diode structure are monolithically integrated within the same chip.

Typical design goals for such RC IGBTs include, for example, a low ohmic connection between the gate electrode and the gate terminal of the RC IGBT receiving the gate signal and a low thermal resistance of the device in both the forward and reverse conducting states.

Disclosure of Invention

According to an embodiment, the RC IGBT comprises: an active region having an IGBT section and a plurality of at least three diode sections; an edge termination region surrounding the active region; a semiconductor body extending in both the active region and the edge termination region and having a front side and a back side, the semiconductor body having a thickness, the thickness being a distance from the front side to the back side in a vertical direction in one of the diode sections; a first load terminal and a control terminal, both at the front side of the semiconductor body; and a second load terminal at the back side of the semiconductor body. Each diode segment is configured to conduct a diode load current between a first load terminal and a second load terminal. The IGBT section is configured to conduct a forward load current between the second load terminal and the first load terminal. The control terminal is electrically connected to a conductive control flow channel structure arranged at the front side of the semiconductor body and extending at least partially along a course of the lateral perimeter of the active region. A plurality of control trenches are arranged parallel to each other along a first lateral direction, and each control trench extends into the semiconductor body along a vertical direction pointing from the front side to the back side. Each control trench has a stripe-like configuration extending along a second lateral direction from a respective first section of the lateral perimeter towards a respective second section of the lateral perimeter opposite the respective first section, wherein the first lateral direction is perpendicular to the second lateral direction. Each control trench houses an insulated control electrode configured to receive a control signal via a control runner structure for controlling the IGBT section. Each control trench is interrupted no more than once by at most a single one of the diode segments along its respective extension in the second lateral direction. In the lateral region of the active region, the diode segments themselves do not overlap one another in the lateral direction and the horizontal projections of the diode segments do not overlap one another in the lateral direction along the second lateral direction either. Within a lateral region of the active region, horizontal projections of the at least two diode segments along the first lateral direction do not overlap each other.

According to another embodiment, a method of processing an RC IGBT includes forming the following components of the RC IGBT: an active region having an IGBT section and a plurality of at least three diode sections; an edge termination region surrounding the active region; a semiconductor body extending in both the active region and the edge termination region and having a front side and a back side, the semiconductor body having a thickness, the thickness being a distance from the front side to the back side in a vertical direction in one of the diode sections; a first load terminal and a control terminal, both at the front side of the semiconductor body; and a second load terminal at the back side of the semiconductor body. Each diode segment is configured to conduct a diode load current between a first load terminal and a second load terminal. The IGBT section is configured to conduct a forward load current between the second load terminal and the first load terminal. The control terminal is electrically connected to a conductive control flow channel structure arranged at the front side of the semiconductor body and extending at least partially along a course of the lateral perimeter of the active region. A plurality of control trenches are arranged parallel to each other along a first lateral direction, and each control trench extends into the semiconductor body along a vertical direction pointing from the front side to the back side. Each control trench has a stripe-like configuration extending along a second lateral direction from a respective first section of the lateral perimeter towards a respective second section of the lateral perimeter opposite the respective first section, wherein the first lateral direction is perpendicular to the second lateral direction. Each control trench houses an insulated control electrode configured to receive a control signal via the control runner structure for controlling the IGBT segments. The processing method includes obeying a design rule according to which: each control trench is interrupted no more than once by at most a single one of the diode segments along its respective extension in the second lateral direction. In the lateral region of the active region, the diode segments themselves do not overlap one another in the lateral direction and the horizontal projections of the diode segments do not overlap one another in the lateral direction along the second lateral direction either. Within a lateral region of the active region, horizontal projections of the at least two diode segments along the first lateral direction do not overlap each other.

The proposed design rules include the following recognition: the above-identified design goals may be achieved by the specific placement of the diode segments within the active region. For example, the proposed rule places the diode section such that a low ohmic connection between the control electrode and the control flow channel structure in the IGBT section and a low thermal resistance for the diode section are achieved.

Those skilled in the art will recognize additional features and advantages upon reading the following detailed description, and upon viewing the accompanying drawings.

Drawings

The components in the figures are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention. Moreover, in the figures, like reference numerals designate corresponding parts. In the drawings:

fig. 1 schematically and exemplarily illustrates a horizontally projected section of an RC IGBT according to one or more embodiments;

fig. 2 schematically and exemplarily illustrates a simplified circuit design of an RC IGBT according to one or more embodiments;

fig. 3 schematically and exemplarily illustrates a section of a vertical cross-section of an IGBT section of an RC IGBT according to one or more embodiments;

fig. 4 schematically and exemplarily illustrates a section of a vertical cross-section of a diode section of an RC IGBT according to one or more embodiments;

fig. 5 schematically and exemplarily illustrates a section of a vertical cross-section of an RC IGBT according to one or more embodiments;

6-9 each schematically and exemplarily illustrates a section of a horizontal projection of an RC IGBT according to one or more embodiments;

fig. 10-11 both schematically and exemplarily illustrate a section of a vertical cross-section of an RC IGBT according to one or more embodiments;

12-15 each schematically and exemplarily illustrates a section of a horizontal projection of an RC IGBT according to one or more embodiments;

fig. 16 schematically and exemplarily illustrates an example of possible shapes of diode sections of an RC IGBT according to some embodiments based on horizontally projected sections;

fig. 17 schematically and exemplarily illustrates a section of a horizontal projection of an RC IGBT according to one or more embodiments;

fig. 18 to 19 both schematically and exemplarily illustrate a section of a vertical cross-section of an RC IGBT according to one or more embodiments; and

both fig. 20 to 21 schematically and exemplarily illustrate a section of a horizontal projection of an RC IGBT according to one or more embodiments.

Detailed Description

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

In this regard, directional terminology, such as "top," "bottom," "below," "front," "back," "leading," "trailing," "over," etc., may be used with reference to the orientation of the figures being described. Because portions of embodiments can be positioned in a number of different orientations, the directional terminology is used for purposes of illustration and is in no way limiting. It is to be understood that other embodiments may be utilized and structural or logical changes may be made without departing from the scope of the present invention. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present invention is defined by the appended claims.

Reference will now be made in detail to the various embodiments, one or more examples of which are illustrated in each figure. Each example is provided by way of explanation, and is not meant as a limitation of the invention. For example, features illustrated or described as part of one embodiment, can be used on or in conjunction with other embodiments to yield yet a further embodiment. It is intended that the present invention include such modifications and variations. The examples are described using specific language, which should not be construed as limiting the scope of the appended claims. The drawings are not to scale and are for illustrative purposes only. For clarity, the same elements or manufacturing steps in different figures are indicated by the same reference signs, if not otherwise stated.

The term "horizontal" as used in this specification intends to describe an orientation substantially parallel to a horizontal surface of a semiconductor substrate or semiconductor structure. This may be, for example, the surface of a semiconductor wafer or die or chip. For example, both the first lateral direction X and the second lateral direction Y mentioned below may be horizontal directions, wherein the first lateral direction X and the second lateral direction Y may be perpendicular to each other.

The term "vertical" as used in this specification intends to describe an orientation arranged substantially perpendicular to a horizontal surface, i.e. parallel to the normal direction of the surface of the semiconductor wafer/chip/die. For example, the extension direction Z mentioned below may be an extension direction perpendicular to both the first lateral direction X and the second lateral direction Y. The direction of extension Z is also referred to herein as the "vertical direction Z".

In this specification, n-doping is referred to as "first conductivity type" and p-doping is referred to as "second conductivity type". Alternatively, the opposite doping relationship may be employed, such that the first conductivity type may be p-doped and the second conductivity type may be n-doped.

In the context of the present specification, the terms "in ohmic contact", "in electrical contact", "in ohmic connection" and "electrically connected" are intended to describe that there is a low ohmic electrical connection or a low ohmic current path between two regions, sections, zones, portions or components of a semiconductor device or between different terminals of one or more devices or between a terminal or metallization or electrode and a portion or component of a semiconductor device. Further, in the context of the present specification, the term "contact" is intended to describe the presence of a direct physical connection between two elements of a respective semiconductor device; for example, a transition between two elements in contact with each other may not include further intermediate elements, and the like.

Furthermore, in the context of the present specification, the term "electrically isolated" is used in the context of its generally valid understanding, if not otherwise stated, and is therefore intended to describe that two or more components are located separately from one another and that there is no ohmic connection connecting these components. However, components that are electrically isolated from each other may still be coupled to each other, e.g. mechanically and/or capacitively and/or inductively coupled. To give an example, the two electrodes of the capacitor may be electrically insulated from each other and at the same time mechanically and capacitively coupled to each other, e.g. by means of an insulator (e.g. a dielectric).

The specific embodiments described in this specification relate to RC IGBTs exhibiting a stripe cell configuration, such as an RC IGBT to be used within a power converter or power supply. Thus, in an embodiment, such an RC IGBT may be configured to carry a load current to be fed to the load and/or a load current provided by the power source accordingly. For example, the RC IGBT may comprise a plurality of power semiconductor cells, such as monolithically integrated diode cells, derivatives of monolithically integrated diode cells, monolithically integrated IGBT cells and/or derivatives thereof. Such diode cells/transistor cells may be integrated in a power semiconductor module. A plurality of such cells may constitute a cell field arranged within the active region of the RC IGBT.

The term "RC IGBT" as used in this specification intends to describe a power semiconductor device on a single chip with high voltage blocking capability and/or high current carrying capability. In other words, embodiments of the RC IGBTs described herein are single chip power semiconductor devices configured for high currents (typically in the ampere range, e.g. up to several amperes or up to several tens or hundreds of amperes) and/or high voltages (typically 100V and above, e.g. up to at least 400V or even higher, e.g. up to at least 3 kV or even up to 10 kV or higher).

For example, the RC IGBTs described below may be single chip power semiconductor devices that exhibit a striped cell configuration and are configured to be employed as power components in low, medium, and/or high voltage applications. Several single chip power RC IGBTs may be integrated in a module to form an RC IGBT module, e.g. for installation and use in low, medium and/or high voltage applications such as primary household appliances, universal drives, electric power transmissions, servo drives, traction, higher power transmission facilities, etc.

For example, the term "RC IGBT" as used in this specification is not directed to logic semiconductor devices used for, for example, storing data, computing data, and/or other types of semiconductor-based data processing.

Fig. 1 schematically and exemplarily illustrates a horizontal projection of an RC IGBT 1 according to one or more embodiments in a simplified manner. The RC IGBT 1 may be, for example, a single-chip RC IGBT. Several such single chip RC IGBTs may be integrated in a power RC IGBT module.

For describing the configuration of the RC IGBT 1, reference will also be made below to fig. 2 to 5.

The RC IGBT 1 comprises an active region 1-2 with a plurality of at least three diode sections 1-22 and IGBT sections 1-21. Both diode sections 1-22 and IGBT sections 1-21 are integrated in the same RC IGBT 1 chip.

An edge termination region 1-3 surrounds the active region 1-2. The edge termination region 1-3 is arranged outside the active region 1-2. The edge termination region 1-3 terminates in the transverse direction with an edge 1-4. The edges 1-4 may form chip edges of the power semiconductor device 1, which result, for example, from a dicing/sawing process step.

As used herein, the terms "edge termination region" and "active region" have the respective technical meanings that are typically associated therewith by those skilled in the art in the context of power semiconductor devices such as RC IGBTs. That is, the active regions 1-2 are primarily configured for forward load current (i.e., "IGBT load current") and reverse load current (i.e., "diode load current") conduction and switching purposes, while the edge termination regions 1-3 primarily fulfill functions with respect to reliable blocking capability, proper guidance of the electric field, and sometimes also a charge carrier draining function and/or further functions with respect to protection and proper termination of the active regions 1-2.

This description relates primarily to active regions 1-2.

As will be set forth in more detail below, the RC IGBT 1 may include an IGBT section 1-21 and a plurality of diode sections 1-22 configured substantially equally. The different sections 1-21 and 1-22 may be laterally distributed within the active region 1-2, examples of such distributions being explained in more detail below.

In an embodiment, the active region 1-2 is composed of a plurality of diode sections 1-22 and one IGBT section 1-21.

It should be understood, however, that according to one or more embodiments described herein, none of the plurality of diode sections 1-22 is integrated into an IGBT section 1-21; therefore, the diode sections 1 to 22 and the IGBT sections 1 to 21 are not mixed with each other. For example, in an embodiment, the diode section 1-22 does not comprise any semiconductor source region (reference numeral 101) of the first conductivity type electrically connected to the first load terminal (reference numeral 11).

For example, the diode sections 1-22 (which, in embodiments, are not integrated into/mixed with the IGBT sections 1-21 and which are not electrically connected to the first load terminal 11 via the source regions 101 of the first conductivity type) constitute a significant part of the active regions 1-2. Thus, according to an embodiment, each of the diode sections 1-22 referred to herein may be a "larger diode only" portion of the active region 1-2.

Regardless of the chosen lateral spatial distribution of the IGBT-regions 1-21 and the diode-regions 1-22, it can be ensured that the ratio between the population of IGBT-regions 1-21 and the population of diode-regions 1-22 is at least 1.5:1, or respectively at least 2:1, i.e. greater than or equal to 2:1, with respect to the volume of the active region 1-2. The ratio chosen may depend on the application in which the power semiconductor device 1 is employed. For example, regardless of the chosen lateral spatial distribution of the IGBT-sections 1-21 and the diode-sections 1-22, it may be ensured that the ratio between the IGBT-section(s) 1-21 and the diode-section(s) 1-22 is even larger than 3:1 or larger than 5:1 with respect to the volume of the active area 1-2.

In an embodiment, at least 75% of the total volume of active regions 1-2 may be occupied to form IGBT sections 1-21, and the remaining 25% (or a lower percentage share) of active regions 1-2 may be taken to form diode sections 1-22.

In an embodiment, the total lateral area (horizontal cross-sectional area) of the diode sections 1-22 forms a fraction of 5% to 40% of the total lateral area (horizontal cross-sectional area) of both the diode sections 1-22 and the IGBT sections 1-21. The lateral region may be defined at the front side 110 of the semiconductor body.

Still further, each diode section 1-22 may have a lateral region and a perimeter defining the lateral region, wherein each diode section 1-22 follows a relationship in which the square of the perimeter divided by the area is less than or equal to 20 or less than or equal to 18.

In the following, reference will also be made to "diode sections 1-22" and "IGBT sections 1-21". It should be understood that the explanations provided below with respect to these sections 1-21 and 1-22 may apply to each section 1-21 provided in the active region 1-2 or to each section 1-22 accordingly. For example, if more than one IGBT section 1-21 is provided, each IGBT section 1-21 may be equally configured (wherein, for example, the respective IGBT sections 1-21 may differ from each other in the overall lateral extension or exhibit the same overall lateral extension). Thus, if a plurality of diode sections 1-22 are provided, each diode section 1-22 may be equally configured (wherein, for example, the respective diode sections 1-22 may differ from each other in or exhibit the same overall lateral extension).

Focusing now also on fig. 2, the semiconductor body 10 of the RC IGBT 1 extends in both the active region 1-2 and the edge termination region 1-3 and has said front side 110 and back side 120. The front side 110 and the back side 120 may vertically terminate the semiconductor body 10. Thus, the thickness d of the semiconductor body 10 is defined as the distance between the front side 110 and the back side 120 along the vertical direction Z. In the lateral direction, the semiconductor body 10 may be terminated by edges 1-4 (see fig. 1). Still further, both the front side 110 and the back side 120 may extend laterally along both the first lateral direction X and the second lateral direction Y. For example, both the front side 110 and the back side 120 may form respective horizontal surfaces of the semiconductor body 10. The thickness d of the semiconductor body 10 may be the distance between the front side 110 and the back side 120 along the vertical direction Z in one of the diode sections 1-22 in the active region 1-2.

In an embodiment, the total lateral extension of the IGBT sections 1-21 amounts to at least 50% of the semiconductor body thickness d. The total lateral extension of the IGBT segments 1-21 may also be more than 50% of the thickness D, for example more than 2 × D or even more than 5 × D.

In an embodiment, the total lateral extension of each of the diode sections 1-22 amounts to at least 20% of the semiconductor body thickness d. The total lateral extension of the diode segments 1-22 may also be more than 30% of the thickness d, for example more than 0.5 x d or even more than d. For example, the lateral region (horizontal cross-sectional region) of each of at least two of the diode sections 1 to 22 has a minimum lateral extension along the first lateral direction X and/or along the second lateral direction Y of at least five times as much as the semiconductor body thickness d.

Both the first load terminal 11 and the control terminal 13 (see fig. 8) are at the semiconductor body front side 110 and the second load terminal 12 is at the semiconductor body back side 120.

IGBT sections 1 to 21 are configured for conducting a forward load current between first load terminal 11 and second load terminal 12, for example if the potential at second load terminal 12 is greater than the potential at first load terminal 11. To control the forward load current, the control terminal 13 is electrically connected to an electrically conductive control flow-path structure 131, the electrically conductive control flow-path structure 131 being arranged at the semiconductor body front side 110 and extending at least partially along the course of the lateral perimeter 1-20 of the active region 1-2, as illustrated in fig. 8.

In an embodiment, a vertical projection of the lateral perimeter 1-20 of the active region 1-2 defines a boundary between the active region 1-2 and the edge termination region 1-3 and/or adjacent active regions (see fig. 21 and associated description).

Each diode section 1 to 22 is configured for conducting a diode load current (also referred to herein as a "reverse load current") between the first load terminal 11 and the second load terminal 12, for example if the potential at the second load terminal 12 is lower than the potential at the first load terminal 11. The diode load current may thus be considered a reverse load current.

In an embodiment, diode sections 1-22 conducting diode load current may be spatially separated from IGBT sections 1-21 conducting forward load current. As indicated above, the diode sections 1-22 are not part of the IGBT sections 1-21 but are separate therefrom and do not comprise, for example, any source regions 101 of the first conductivity type electrically connected to the first load terminal 11; in contrast, according to some embodiments, diode segments 1-22 are "large diode only regions" of active regions 1-2.

For example, in an embodiment, the path of the forward load current formed in the semiconductor body 10 and the path of the diode load current formed in the semiconductor body 10 do not spatially significantly overlap one another. For example, no forward (IGBT) load current or less than 20% or even less than 10% of the forward (IGBT) load current flows through diode sections 1-22.

Further, in an embodiment, the diode segments 1-22 are independent of a control signal (e.g., a control signal provided to the control electrode 141 mentioned below). For example, the diode section 1-22 may be configured such that it conducts the diode load current as soon as the potential (of typical polarity) at the second load terminal 12 is lower than the potential at the first load terminal 11 (at least by the diode section internal threshold voltage), irrespective of the control signal provided to the IGBT section 1-21, i.e. irrespective of the present potential of the control electrode 141.

According to terminology typically associated with RC IGBTs, the control terminal 13 may be a gate terminal, the first load terminal 11 may be an emitter terminal, and the second load terminal 12 may be a collector terminal.

For example, the first load terminal 11 comprises a front side metallization and/or the second load terminal 12 comprises a back side metallization. For example, the first load terminal 11 is an emitter terminal and the second load terminal 12 is a collector terminal. At the front side 110, the semiconductor body 10 can be interfaced with a front-side metallization. At the back side 120, the semiconductor body 10 can be connected to a back-side metallization.

In an embodiment, the first load terminal 11 (e.g. the front side metallization) overlaps the active area 1-2 in a lateral direction, i.e. along the first lateral direction X and/or the second lateral direction Y and/or combinations thereof. It should be noted that the first load terminal 11 may be structured in a lateral direction, for example in order to establish a local contact with the semiconductor body 10 at the front side 110. For example, as exemplarily illustrated in fig. 3 and 4, the local contact may be established by means of a first contact plug 111 penetrating the insulating structure 19 so as to contact the mesa portion 17 formed in the semiconductor body 10.

Similarly, in an embodiment, the second load terminal 12 (e.g. the backside metallization) overlaps the active region 1-2 in a lateral direction, i.e. along the first lateral direction X and/or the second lateral direction Y and/or combinations thereof. It should be noted that the second load terminal 12 is typically not structured but is formed uniformly and monolithically at the semiconductor body back side 120, for example in order to establish a laterally uniform contact (i.e. a continuous contact surface) with the semiconductor body 10 at the back side 120. Such a uniform structure may also be realized in a region in which the second load terminal 12 laterally overlaps the edge termination regions 1-3.

For example, the lateral boundaries of the active regions 1-2 are defined by the lateral boundaries of the outermost power cells of the IGBT sections 1-21. Thus, the lateral boundaries of the active regions 1-2 may be defined at the front side 110. For example, the lateral boundary may be defined by the outermost source region 101 (see more detailed explanation below). For example, all functional elements enabling conduction of the diode load current and the forward load current are present in the vertical projection of the active region 1-2 of the power semiconductor device 1, for example including at least a part of the first load terminal 11 (e.g. its front-side metal contact, e.g. one or more of the first contact plugs 111), the source region(s) 101, the body region 102, the drift region 100, the IGBT emitter region 103, the diode cathode region 104 and the second load terminal 12 (e.g. its back-side metal), as will be explained in more detail below.

In an embodiment, the edge termination region 1-3 and the active region 1-2 may be arranged substantially symmetrically, e.g. about a central vertical plane of the RC IGBT 1.

Still further, according to an embodiment, the lateral transition (along the first lateral direction X or the second lateral direction Y or a combination thereof) between the active region 1-2 and the edge termination region 1-3 may extend exclusively along the vertical direction Z. As explained above, the lateral boundaries of the active regions 1-2 can be defined at the front side 110, and thus a vertical projection of the thus defined lateral boundaries along the vertical direction Z can theoretically be observed at the back side 120, wherein the second load terminals 12 at the back side 120 are for example not structured but formed uniformly in the lateral direction.

Referring now in more detail to fig. 3-5, a plurality of control trenches 14 are arranged in IGBT zones 1-21. The control trenches 14 are arranged parallel to one another along a first lateral direction X and extend into the semiconductor body 10 along a vertical direction Z. Each control trench 14 has a stripe configuration extending along the second transverse direction Y from a respective first section of the transverse perimeters 1-20 (refer to fig. 1) towards a respective second section of the transverse perimeters 1-20 opposite the respective first section. Each control trench 14 houses an insulated control electrode 141, the insulated control electrode 141 being configured to receive a control signal via the control flow channel structure 131 (see e.g. fig. 6) for controlling the IGBT segments 1-21.

The control electrodes 141 are isolated from the semiconductor body 10 by respective trench insulators 142.

Two adjacent trenches 14 may define respective mesa portions 17 in the semiconductor body 10.

Each control trench 14 may have a stripe-like configuration, e.g. as best illustrated in one of the horizontal/perspective projections in e.g. fig. 6 and 8, meaning that the respective trench length (e.g. along the second lateral direction Y) is much larger than the respective trench width (e.g. along the first lateral direction X).

As will be explained further below, a further trench may be provided which accommodates a trench electrode having a different potential than the potential of the control electrode 141.

The first type of trench may be a control trench 14 whose trench electrode 141 is electrically connected to the control terminal 13 and is therefore referred to as control electrode 141.

The second type of trench may be a source trench 16, whose trench electrode 161 is electrically connected to the first load terminal 11 and is therefore referred to as source electrode 161.

The third type of trench may be a further trench whose trench electrode is electrically connected neither to the first load terminal 11 nor to the control terminal 13. For example, in one embodiment, such a trench is a floating trench, and its trench electrode is not connected to a defined potential but electrically floating. In another embodiment, such a trench is a dummy trench, and its trench electrode is electrically connected to the control terminal 13 but does not directly control the conduction of the forward load current, because the source region 101 without an electrical connection (connected to the first load terminal) is arranged adjacent to the trench of the third type. In a further embodiment, the trench electrodes of the trenches of the third type are connected to a potential different from the potential of the control terminal 13 and different from the potential of the first load terminal 11.

Each trench type may have equal dimensions in terms of width (along the first lateral direction X) and depth (along the vertical direction Z, e.g. the distance between the front side 110 down to the trench bottom) and/or length (along the second lateral direction Y, where some trenches may be interrupted by diode segments along their course in the second lateral direction Y, as will be described below).

The IGBT-sections 1-21 may comprise a plurality of IGBT-cells, each having a specific trench pattern, i.e. a lateral sequence (along the first lateral direction X) of trenches of a specific type, e.g. one or more control trenches 14, zero or more source trenches 16 and zero or more further trenches.

Similarly, each diode region 1-22 may include a number of diode cells, each having a particular trench pattern, i.e., a lateral sequence of a particular type of trench (e.g., zero or more source trenches 16 and/or zero or more other trenches).

In another embodiment, no trenches with trench electrodes are provided in the diode sections 1 to 22, for example such that each diode section 1 to 22 has only one diode cell (as illustrated for example in fig. 5). In an embodiment, each diode section 1-22 does not include a trench having a trench electrode electrically connected to control terminal 13. For example, none of the control trenches 14 extend into one or more of the diode sections 1-22. For example, the diode regions 1-22 are thus separated from both the IGBT regions 1-21 and from the control trench 14 (i.e. from the control trench electrode 141), which may allow to achieve "good" diode characteristics, such as little or no dependence on the potential of the control electrode 141 and/or low switching losses.

If trenches are provided in the diode sections 1-22, for example trenches different from those whose trench electrodes are electrically connected to the control terminal 13, it may be provided that the trenches in both the IGBT sections 1-21 and the diode sections 1-22 are arranged laterally one next to the other with the same lateral trench spacing; that is, according to an embodiment, the lateral trench spacing (i.e., the distance between two adjacent trenches along the first lateral direction X) does not change between sections 1-21 and sections 1-22.

In an embodiment, the lateral trench spacing may define a lateral distance between two adjacent trenches of not more than 1/30 of the semiconductor body thickness d.

Further, in embodiments, each of the grooves 14, 16 may exhibit the same groove depth (overall vertical extension). For example, the lateral trench spacing may define a lateral distance between two adjacent trenches that is no greater than 50% of the trench depth or no greater than 30% of the trench depth.

In embodiments, the lateral trench spacing may define a lateral distance between two adjacent trenches of no more than 10 μm, or no more than 5 μm, 1 μm, or no more than 1 μm. For example, adjacent trenches are thus laterally displaced from each other by no more than 1 μm.

Thus, at least in IGBT sections 1-21, the width of each mesa portion 17 is within a range as defined by the lateral trench pitch.

As explained above, the lateral trench spacing may be the same for both sections 1-21 and sections 1-22, or the lateral trench spacing may vary between sections. For example, the average density of the trench electrodes may also be the same for both segments 1-21 and segments 1-22. However, the groove pattern (e.g., arrangement of different types of grooves) may vary between sections 1-21 and sections 1-22. One exemplary variation is that the density of the control electrodes 141 in the IGBT sections 1-21 is at least twice as high as the density of the control electrodes 141 in the diode sections 1-22 (which may even reach zero).

In the illustrative example, the total number of trench electrodes in IGBT sections 1-21 is 120 and 40 trench electrodes are control electrodes 141, resulting in a control electrode density of 30%. For example, the total number of trench electrodes in diode segments 1-22 is 100, and no more than ten trench electrodes are control electrodes 141, resulting in a control electrode density of no more than 10%. In an embodiment, the trench electrodes in diode sections 1-22 do not include any control trench electrodes 141.

In an embodiment, at least 50% of the trench electrodes of the trenches in the diode regions 1-22 are electrically connected to the first load terminal 11, i.e. at least 50% of the trench electrodes of the trenches in the diode regions 1-22 are trench electrodes 161 of the source trench 16.

For example, the trenches in the diode regions 1-22 are either source trenches 16 or floating trenches 15, e.g. all trenches in the diode regions 1-22 are source trenches 16. Still further, all or some of the mesa portions 17 in the diode sections 1 to 22 may be electrically connected to the first load terminal 11, for example by means of first contact plugs 111.

In contrast, the trench type in IGBT zones 1-21 may vary; according to an embodiment, a subsequently repeated trench mesa pattern corresponding to "kgksososs" may be employed for forming the IGBT-cell, wherein "k" denotes the mesa portion 17 connected to the first load terminal 11, "o" denotes the mesa portion 17 not connected to the first load terminal 11 (i.e. meaning that the transition between the first load terminal 11 and the mesa portion 17 in the vertical direction Z is non-conductive), "G" denotes the gate trench 14, and "S" denotes the source trench 16. Of course, different trench mesa patterns may be used in other embodiments. For example, dummy trenches (which are identical to the gate trenches arranged between the non-contact mesa portions 17) may be included in the pattern of the diode regions 1-22 and/or in the pattern of the IGBT regions 1-21. Again, it is emphasized that according to some or all embodiments described herein, diode segments 1-22 do not include any control trench electrode 141 or any other trench electrode (e.g., dummy trench electrode) electrically connected to control terminal 13.

Still referring to fig. 3 to 5, and additionally to fig. 7, the RC-IGBT 1 further comprises a drift region 100 of the first conductivity type formed in the semiconductor body 10 and extending into the diode regions 1-22 and the IGBT regions 1-21.

Body regions 102 of the second conductivity type are formed in (the mesa portions 17, if present) the semiconductor body 10 of the diode regions 1-22 and the IGBT regions 1-21. At least part of the body region 102 is electrically connected to the first load terminal 11. The body region 102 may form a pn-junction for a sub-section of the mesa portion 17 of the first conductivity type. For example, not in each mesa portion 17 a respective portion of the body region 102 is electrically connected to the first load terminal 11 so as to form "dummy mesa portions", i.e. those mesa portions which are not used for load current conduction.

In the IGBT sections 1 to 21, a source region 101 of the first conductivity type is arranged at the front side 110 and is electrically connected to the first load terminal 11. The source regions 101 are for example only locally provided in the IGBT regions 1 to 21 and do not extend for example into the diode regions 1 to 22.

The body region 102 may be arranged to be in electrical contact with the first load terminal 11, for example by means of a first contact plug 111. In each IGBT cell of the IGBT sections 1 to 21, at least one source region 101 of the first conductivity type may further be provided, which is arranged to be in electrical contact with the first load terminal 11, for example also by means of the first contact plug 111. A main part of the semiconductor body 10 is formed as a drift region 100 of the first conductivity type, which may adjoin the body region 102 and form therewith a pn-junction 1021. The body region 102 isolates the source region 101 from the drift region 100. Here, the term "body region 102" refers to a semiconductor region of the second conductivity type which is electrically connected to the first load terminal 11 at the front side 110. This region extends into both the IGBT sections 1 to 21 and the diode sections 1 to 22 (which may therefore also be referred to there as "diode anode regions" or the like). The implementation of the body region 102 in the IGBT-sections 1-21 may differ from the implementation of the body region 102 in the diode-sections 1-22, for example in terms of dopant concentration, dopant dose, dopant profile and/or spatial extension.

Upon receiving a corresponding control signal, e.g. provided by a not shown gate driver unit, each control electrode 141 may induce an inversion channel in a section of the body region 102 adjacent to the respective control electrode 141. Accordingly, each of the plurality of IGBT cells may be configured to conduct at least a portion of the forward load current between the first load terminal 11 and the second load terminal 12.

The basic configuration of the IGBT cells in the IGBT sections 1 to 21 of the power semiconductor device 1 described above as such is known to those skilled in the art, and the present specification adopts the term "IGBT cell" within the technical meaning typically associated therewith by those skilled in the art.

In an embodiment, the drift region 100 extends along the vertical direction Z until it meets the field stop layer 108, wherein the field stop layer 108 is also of the first conductivity type, but exhibits a higher dopant dose as compared to the drift region 100. The field stop layer 108 typically has a significantly smaller thickness than the drift region 100.

The drift region 100 or, if present, the field stop layer 108 extends in the vertical direction Z until meeting with the IGBT emitter regions 103 of the IGBT segments 1 to 21 or the diode cathode regions 104 of the diode segments 1 to 22.

The diode cathode region 104 is of the first conductivity type and is electrically connected to the second load terminal 12 and is coupled to the drift region 100, for example by means of a field stop layer 108.

The IGBT emitter region 103 is of the second conductivity type and is electrically connected to the second load terminal 12 and is coupled to the drift region 100, for example by means of a field stop layer 108.

Both the IGBT emitter region 103 of the IGBT zones 1 to 21 and the diode cathode region 104 of the diode zones 1 to 22 may be arranged in electrical contact with the second load terminal 12.

In general, the IGBT emitter region 103 may function as an emitter of the second conductivity type. Still further, the IGBT emitter region 103 does not include any segments of the first conductivity type in some embodiments, which exhibit a relatively high dopant concentration, typically at 10¹⁶ cm^-3To 10²⁰ cm^-3Within the range of (1); in contrast, according to some embodiments, the diode cathode region 104 is formed exclusively in the diode segments 1-22.

In an embodiment, the average dopant concentration of the drift region 100 may be at 10¹² cm^-3To 10¹⁴ cm^-3Within the range of (1).

In an embodiment, the dopant concentration of each source region 101 in IGBT zones 1-21 may be at 10¹⁹ cm^-3To 10²¹ cm^-3Within the range of (1).

In an embodiment, the dopant concentration of the body region 102 may be at 10¹⁶ cm^-3To 10¹⁸ cm^-3Within the range of (1). As described above, for example, the dopant concentration of body regions 102 in IGBT zones 1-21 may be different from the dopant concentration of body regions 102 in diode zones 1-22.

In an embodiment, the dopant concentration of the (optional) field stop layer 108 may be at 10¹⁴ cm^-3To 3 x 10¹⁶ cm^-3Within the range of (1).

In an embodiment, the dopant concentration of the IGBT emitter region 103 may be at 10¹⁶ cm^-3To 10¹⁸ cm^-3Within the range of (1). However, in an embodiment, the dopant concentration may vary along the lateral extension of the IGBT emitter region 103.

In an embodiment, the dopant concentration of the diode cathode region 104 may be at 10¹⁹ cm^-3To 10²¹ cm^-3Within the range of (1). However, in embodiments, the dopant concentration may vary (and even change polarity) along the lateral extension of the diode cathode region 104.

It should be noted that the trench patterns illustrated in fig. 3 and 4 are merely exemplary; other trench patterns are possible.

In an embodiment, the diode regions 1-22 are not provided with source regions 101. For example, in diode regions 1-22, there is no doped semiconductor region of the first conductivity type electrically connected to the first load terminal. In contrast, in order to form a diode arrangement for conducting a diode load current in the diode sections 1 to 22, only the body region 102 is electrically connected to the first load terminal 11, wherein the body region 102 forms a pn junction 1021 with, for example, the drift region 100 and in the vertical direction Z towards the second load terminal 12, below which pn junction 1021 there is a semiconductor path of only the first conductivity type which is not interrupted by any further regions of the second conductivity type.

As explained above, according to an embodiment, the IGBT-regions 1-21 comprise at least one IGBT-cell, in contrast to the diode-regions 1-22, wherein a region of the source region 101 is connected to the first load terminal 11 and is arranged adjacent to one of the control trenches 14 and is isolated from the drift region 100 by the body region 102. For example, the lateral boundaries of IGBT sections 1-21 are defined by the lateral boundaries of the outermost IGBT cell(s). Thus, the lateral boundaries of the IGBT sections 1-21 may be defined at the front side 110. The lateral boundary may be defined by the outermost source region(s) 101. For example, all functional elements enabling conduction of a forward load current are present in the vertical projection of the IGBT sections 1-21 of the power semiconductor device 1, for example including at least the first load terminal 11 (e.g. its front side metal contact, e.g. one or more of the first contact plugs 111), the source region(s) 101, the body region 102, the drift region 100, the IGBT emitter region 103 and the second load terminal 12 (e.g. its back side metal). Still further, the functional elements may extend along the entire lateral extension of the IGBT sections 1-21.

In an embodiment, the first contact plug 111 is part of a contact plug structure of the power semiconductor device 1. Each first contact plug 111 may be configured to establish contact with a corresponding mesa portion 17 so as to electrically connect the corresponding mesa portion 17 to the first load terminal 11. As illustrated, each first contact plug 111 may extend in the vertical direction Z from the front side 110 into the respective mesa portion 17.

Fig. 6 to 9 schematically and exemplarily illustrate a section of a horizontal projection of the RC IGBT 1 according to some embodiments. Each of these embodiments may be configured in accordance with the foregoing explanations.

For example, in each of these embodiments, the RC IGBT comprises: an active region 1-2 having an IGBT section 1-21 and a plurality of at least three diode sections 1-22; an edge termination region 1-3 surrounding the active region 1-2; a semiconductor body 10 extending in both the active region 1-2 and the edge termination region 1-3 and having a front side 110 and a back side 120; a first load terminal 11 and a control terminal 13, both at the semiconductor body front side 110; and a second load terminal 12 at the back side 120 of the semiconductor body. Each diode section 1-22 is configured for conducting a diode load current between the first load terminal 11 and the second load terminal 12. IGBT sections 1-21 are configured to conduct a forward load current between second load terminal 12 and first load terminal 11. The control terminals 13 are electrically connected to electrically conductive control flow channel structures 131, the electrically conductive control flow channel structures 131 being arranged at the semiconductor body front side 110 and extending at least partially along the course of the lateral perimeter of the active regions 1-2. The plurality of control trenches 14 are arranged parallel to each other along a first lateral direction X and each extend into the semiconductor body along a vertical direction Z pointing from the front side 110 to the back side 120. Each control trench 14 has a stripe-like configuration extending from a respective first section of the lateral perimeters 1-20 towards a respective second section of the lateral perimeters 1-20 opposite the respective first section along a second lateral direction Y, wherein the first lateral direction X is perpendicular to the second lateral direction Y. Each control trench 14 houses a respective insulated control electrode 141 configured to receive a control signal via the control flow channel structure 131 for controlling the IGBT segments 1-21.

In the above, many possible configurations of the diode sections 1-22 and the IGBT sections 1-21 have been proposed. These possible configurations may also be implemented in the embodiments illustrated in fig. 6 to 9.

In an embodiment, the arrangement of the diode sections 1-22 occurs according to a design rule. The rules are specified as follows:

each control trench 14 is interrupted not more than once by at most a single one of the diode sections 1-22 along its respective extension in the second lateral direction Y (see fig. 6);

in the lateral region of the active region 1-2, the individual diode segments 1-22 do not themselves overlap each other laterally and the horizontal projections of these diode segments do not overlap each other laterally along the second lateral direction Y either (indicated with a dashed line in fig. 7);

still further, within the lateral area of the active region 1-2, the horizontal projections along the first lateral direction X of at least two of the diode sections 1-22 do not overlap each other (indicated with dashed lines in fig. 9). As is illustrated by way of example in fig. 9, the X horizontal projection of the diode section 1 to 22 illustrated in the lower part of the figure does not overlap the X horizontal projections of the two further diode sections 1 to 22.

Fig. 8 exemplarily illustrates aspects of the RC IGBT 1 related to the control terminal 13. The control terminal 13 may include a pad 135, the pad 135 being disposed at a corner at the front side of the active region 1-2 and configured to be contacted by a control signal transmission member (e.g., a bonding wire, etc.).

The runner structures 131 may originate from the pads 135 and extend along the path of the lateral perimeters 1-20 of the active areas 1-2 in a strip-like manner, for example, as follows: each control electrode 141 of each uninterrupted control trench 14 may be electrically contacted at its two ends (with respect to the second lateral direction Y) located near the lateral perimeter 1-20 of the active area 1-2. This allows, for example, avoiding the need to contact the control electrode 141 within the active region 1-2.

What has been explained with regard to fig. 6 to 9 can equally or correspondingly be applied in a similar manner to the embodiments illustrated in the remaining fig. 10 to 21.

Both fig. 10 and 11 schematically and exemplarily illustrate a section of a vertical cross-section of an RC IGBT 1 according to some embodiments.

According to fig. 10, both control trenches 14 and source trenches 16 are provided in the IGBT regions 1 to 21 and are arranged in an alternating manner. That is, every other trench is a source trench 16 and every other trench is a control trench 14. The source trench electrode 161 is electrically connected to the first load terminal 11 via at least the second contact plug 112, while at least the first contact plug 111 establishes electrical connection between the mesa portion 17 and the first load terminal 11. As illustrated, the trench patterns in adjacent diode sections 1-22 (and for example also in each further diode section 1-22) differ in that only the active trench 16 is provided and no control trench 14 is provided. However, the trench spacing is unchanged. Therefore, the contact plug structure is modified for the diode section, because each trench electrode, which is the source trench electrode 161, is electrically connected to the first load terminal 11 through the corresponding second contact plug 112. Further, in the diode regions 1-22 it is ensured that no source region 101 is provided but that the first contact plug contacts only the body region 102. For example, since every other trench electrode in IGBT zones 1-21 is source trench electrode 161, the total gate capacity of RC IGBT 1 is reduced. Further, since the trench pitch is maintained in the diode sections 1 to 22, a uniform etching process can be applied when producing the RC IGBT 1.

The IGBT sections 1 to 21 of the embodiment illustrated in fig. 11 are configured identically to the IGBT sections 1 to 21 illustrated in fig. 10. However, in the diode sections 1 to 22, no trench is provided at all. In contrast, the body region 102 extends continuously (e.g., uninterrupted by trenches) within the diode regions 1-22 and is separated from the first load terminal 11 by an insulating layer 191. The insulating layer 191 is penetrated by the first contact plug 111 that establishes electrical connection between the body region 102 and the first load terminal 11. Alternatively, as shown in fig. 5, the electrical connection may be established without a contact plug. Not providing trenches in the diode sections 1-22 may be advantageous for the switching characteristics of the diode sections 1-22.

Each of fig. 12 to 17 schematically and exemplarily illustrates a section of a horizontal projection of the RC IGBT 1 according to some embodiments.

The illustrated embodiment according to fig. 12 corresponds to the embodiment shown in fig. 11; both control trenches 14 and source trenches 16 are provided in the IGBT regions 1-21 and are arranged there in an alternating manner. That is, every other trench is a source trench 16 and every other trench is a control trench 14. The source trench electrode 161 is electrically connected to the first load terminal 11 via at least the second contact plug 112, while at least the first contact plug 111 establishes electrical connection between the mesa portion 17 and the first load terminal 11 (not shown in fig. 12). Neither trench 14, 16 extends into a diode section 1-22. Each trench 14, 16, which does not extend continuously along the entire extension of the active region 1-2 in the second lateral direction Y but is "interrupted" by (or ends at respectively one of the diode sections 1-22), is terminated such that it is spatially displaced from the respective diode section 1-22, for example by at least a specified minimum distance, as will be explained further below. The structure of the control terminal 13 corresponds to that illustrated in fig. 8, and therefore it is referred to the above explanation here.

Fig. 13 illustrates a variant in which five diode sections 1-22 are provided in the active region 1-2. However, regardless of the number of selected diode regions 1-22, and regardless of the selected trench pattern in the IGBT regions 1-21 and the diode regions 1-22 (if implemented there) and further regardless of the structure of the control terminal 13 (not shown), fig. 13 exemplarily illustrates an optional further specification of a design rule for arranging the diode regions 1-22 in the active region 1-2, according to which the lateral distance xy1 between any one of the diode regions 1-22 and the edge termination region 1-3 at least reaches the semiconductor body thickness d.

The lateral distance xy1 may even be greater than d, such as greater than 2 x d, or greater than 5 x d. For example, this further provision includes recognizing that high commutation robustness may be required for commutation in hard switching applications (e.g. driving); the diode section directly adjacent to the edge termination region 1-3 may be less robust because during commutation, a higher current density flows there due to the additional electron-hole plasma extracted from the edge termination region 1-3.

Alternatively or in addition to the above-described optional further provision of the design rule for arranging the diode sections 1 to 22 in the active region 1 to 2, the design rule may specify that the lateral distance xy2 between any one of the diode sections 1 to 22 to another one of the diode sections 1 to 22 at least amounts to the semiconductor body thickness d. The lateral distance xy2 may even be larger than d, for example larger than 4 x d or larger than 8 x d. This optional additional provision subject to design rules may contribute to a uniform distribution of the diode sections 1-22 within the active region 1-2 and an improved characteristic output curve of the RC IGBT 1.

Although at least three spatially distributed diode sections 1-22 are provided in the active region 1-2, in an embodiment there is only one IGBT section 1-21 in the active region 1-2, and the IGBT sections 1-21 may be continuous within the active region 1-2, such that a single IGBT section 1-21 (and no diode sections 1-22) forms a transition to the edge termination region 1-3, and such that a single IGBT section 1-21 surrounds each of the at least three diode sections 1-22.

The embodiment illustrated in fig. 14 and 15 corresponds to the embodiment illustrated in fig. 12, wherein neither trench 14, 16 extends into the diode regions 1-22, wherein the source trench 16 is not depicted in fig. 14 and 15 (only one in the enlarged region). Fig. 14 and 15 illustrate two variations of how the trenches 14, 16 may terminate near the respective diode sections 1-22.

For example, the control trench 14 is composed of an uninterrupted control trench and a control trench interrupted once by a respective one of the diode sections 1-22. The uninterrupted control trench may extend continuously along the second lateral direction Y from one section of the lateral perimeters 1-20 to the opposite section of the lateral perimeters 1-20. If source trenches 16 are provided, a similar definition applies if source trenches 16 do not extend into diode regions 1-22 either.

Accordingly, the control electrode 141 in the uninterrupted control trench 14 may continuously extend along the second lateral direction Y, and the control electrode 141 in the interrupted control trench may be divided into the first control electrode 1411 and the second control electrode 1412 as follows: the first control electrode 1411 is in a first control trench portion before the respective diode segment 1-22 with respect to the second lateral direction Y; the second control electrode 1412 is in a second control trench portion after the respective diode segment 1-22 with respect to the second lateral direction Y, as schematically and exemplarily illustrated in fig. 6, 8, 13, 14, 15. If a source trench 16 is provided, a similar definition applies if the source trench 16 does not extend into the diode regions 1-22 either. It should be noted that in contrast to the schematic illustrations in fig. 14 and 15 (and in the other figures), the portions of the interrupted trenches before and after the respective diode segments may be offset from each other with respect to the first lateral direction X, instead of being arranged along the same line in the second lateral direction Y (as illustrated).

Each control electrode 141, 1411, 1412 has two lateral ends with respect to the second lateral direction Y. For example, referring to fig. 14 and 15, the control electrode 141 of the uninterrupted control trench 14 has a first lateral end terminating at a "lower" (with respect to the second lateral direction Y) section of the control flow structure 131 and electrically connected to the "lower" section of the control flow structure 131, and a second lateral end terminating at an "upper" (with respect to the second lateral direction Y) section of the control flow structure 131 opposite the "lower" section and electrically connected to the "upper" section of the control flow structure 131 opposite the "lower" section.

That is, in an embodiment, each control electrode 141 in the uninterrupted control trench 14 is electrically connected at its respective two lateral ends to the potential of the control terminal 13 by means of a respective first conductive structure extending along the first lateral direction X and a respective second conductive structure extending along the first lateral direction X. With respect to the control electrode 141 in the uninterrupted control trench 14, a first conductive structure is formed by the "lower" section of the control flow channel structure 131 and a second conductive structure is formed by the "upper" section of the control flow channel structure 131.

Still further, in an embodiment, each of the first 1411 and second control electrodes 1412 in the interrupted control trench 14 is also electrically connected at their respective two lateral ends to the potential of the control terminal 13 by means of a respective first conductive structure extending along the first lateral direction X and a respective second conductive structure extending along the first lateral direction X.

With respect to the first control electrode 1411 in the interrupted control trench 14 before the respective diode section 1-22, a first electrically conductive structure is formed by said "lower" (in terms of e.g. the second lateral direction Y in fig. 14) section of the control channel structure 131.

With respect to the second control electrode 1412 in the interrupted control trench 14 after the respective diode segment 1-22, a second conductive structure is formed by said "upper" segment of the control flow channel structure 131.

With respect to the lateral ends of the first and second control electrodes 1411, 1412 in the interrupted control trench 14, which terminate before and after the respective diode section 1-22 and in the vicinity of the respective diode section 1-22 (and not at the control flow channel structure 131), each electrically conductive structure establishing an electrical connection to the potential of the control terminal 13 may be realized by means of a crossing trench structure 18 arranged in the vicinity of the diode section 1-22 and extending at least partially along the first lateral direction X. An example of an intersecting trench structure 18 arranged near the diode sections 1-22 and extending at least partially along the first lateral direction X is depicted in the enlarged sections of fig. 14 and 15, both showing the area before (with respect to the second lateral direction Y) the diode sections 1-22, i.e. in case of the first control electrode 1411 of the interrupted control trench 14. In the example shown in fig. 15, as illustrated, the interdigitated trench structure 18 preceding the respective diode region 1-22 extends continuously to establish a connection for all first control trench electrodes 1411 of all first trench portions of the control trench 14 (which end before the respective diode region 1-22), and thus, the interdigitated trench structure 18 following the respective diode region 1-22 extends continuously to establish a connection for all second control electrodes 1412 of all second trench portions of the control trench 14 (which end after the respective diode region 1-22). In contrast, in the example shown in fig. 14, as illustrated, a respective plurality of intersecting trench structures 18 are provided both before and after the respective diode sections 1-22, and each intersecting trench structure 18 connects only the control trench electrodes 1411 (or respectively the control trench electrodes 1412) in two adjacent control trenches 14 to each other.

The embodiment illustrated in fig. 14 and 15 comprises said source trenches 16, wherein the control trenches 14 and the source trenches 16 are provided only in the IGBT-regions 1-21 (and not in the diode-regions 1-22) and are arranged there in an alternating manner. That is, in IGBT zones 1 to 21, every other trench is a source trench 16, and every other trench is a control trench 14. The source trench electrode 161 is electrically connected with the first load terminal 11 via at least the second contact plug 112, as already explained with respect to the previous figures (e.g., fig. 10 and 11).

In an embodiment, the intersection trench structures 18 are arranged so as to establish respective "U-turns" around the lateral ends of the respective source trench electrodes 161, as illustrated in both fig. 14 and 15. For example, each or at least one of the source trenches 16 is interrupted by a respective one of the diode regions 1-22, the source trench 16 or respectively each source trench 16 is arranged between two interrupted control trenches 14, and the (respective) crossing trench structure 18 is moved away from the end of the source trench 16 along the second lateral direction Y. It should be noted, however, that the concept of using the intersection trench structure 18 to electrically connect the ends of adjacent first/second control trench electrodes 1411/1412 terminating near one of the diode regions 1-22 may also be implemented if there is more than one source trench 16, if there are one or more other types of trenches, or if no trenches are provided at all between adjacent control trenches 14.

According to an embodiment, if source trenches 16 are provided, it may be ensured that no source trenches 16 extend into one or more diode regions 1-22 and/or that each source trench 16 is interrupted no more than once by at most a single one of the diode regions 1-22 along its respective extension in the second lateral direction Y. In other embodiments, one or more source trenches 16 may extend into one or more diode regions 1-22, as already explained above.

To establish the connection of adjacent control trenches 14, each intersecting trench structure 18 may be provided with a chamfer (as illustrated in fig. 14) or extend only along the first lateral direction X such that the control trench 14 accommodating the control electrode 1411 and the intersecting trench structure 18 form a substantially right-angled turn (as illustrated in fig. 15). Also as illustrated in fig. 15, a "T-junction" may be formed with adjacent uninterrupted control trenches.

To establish electrical connection of adjacent control trenches 1411, each intersecting trench structure 18 may include an intersecting trench electrode 181 that electrically connects a first control electrode 1411 (as illustrated) of two adjacent interrupted control trenches 14 before diode segments 1-22 or a second control electrode 1412 of two adjacent interrupted control trenches 14 after diode segments 1-22, respectively.

The use of the interdigitated trench structure 18 near the diode regions 1-22 reduces the risk of floating first/second control electrodes 1411/1412; for example, according to an embodiment, if the electrical connection at the lateral end at the control flow channel structure 131 is lost/not established for some reason, the affected first or second control electrode 1411/1412 may still be electrically connected to the potential of the control terminal 13 due to the electrical connection established with the intersecting trench structure 18 to the adjacent first or second control electrode 1411/1412. Therefore, the RC IGBT 1 can exhibit high reliability and controllability.

Fig. 16 schematically and exemplarily illustrates examples of possible shapes of the diode sections 1-22 of the RC IGBT 1 according to some embodiments based on horizontally projected sections. For example, at least one or each of the at least three diode sections 1 to 22 may exhibit a square lateral area, i.e. a horizontal cross section (variant (a)), e.g. with rounded corners or provided with beveled corners (not shown). In another example, at least one or each of the at least three diode sections 1-22 may present a rectangular lateral area, i.e. a horizontal cross section (variant (b)), e.g. corners with rounded corners or corners provided with beveled corners (not shown). In another example, at least one or each of the at least three diode sections 1 to 22 may exhibit a circular lateral area, i.e. a horizontal cross section (variant (c)). In another example, at least one or each of the at least three diode sections 1-22 may exhibit an elliptical lateral area, i.e. a horizontal cross-section (not shown variant). In an embodiment, differently shaped diode sections 1-22 may be combined within the active region 1-2 of the RC IGBT 1.

For example, the shape of the diode sections 1-22 is suitable, which provides a large lateral area (= horizontal cross-sectional area), but has a small perimeter defining it. For example, if rectangular horizontal cross sections are chosen (variant (b)), these should be designed with a small difference between the total lateral extension ly and lx. This embodiment is based on the recognition that: since in the conducting state of the RC IGBT 1 (especially the diode conducting state, when a reverse/diode load current flows) charge carriers may be lost through the boundary between the IGBT sections 1-21 and the diode sections 1-22 and contribute less to the current flow but still to the switching losses. Thus, according to an embodiment, the diode sections 1-22Has the following shape: this shape has a large lateral area but a small perimeter, i.e. has a "short boundary" to the IGBT sections 1-21. Against this background, the above-described embodiment of the RC IGBT 1 according to which each diode section 1 to 22 has a lateral region (= horizontal cross-sectional region) and a perimeter defining the lateral region, wherein each diode section 1 to 22 obeys the relationship of the square of the perimeter divided by the area being smaller than or equal to 18. Of course, a circular shape is optimal in this respect; for (perimeter)²It has a value of 4 pi ≈ 12.57 in terms of area. The square shape (square) reaches a value of 16 and the rectangle with side length ratio ly/lx =2 reaches 18.

Fig. 17 schematically and exemplarily illustrates a section of a horizontal projection of the RC IGBT 1 according to one or more embodiments. There, each diode section 1-22 is separated from the IGBT section 1-21 by means of a substantially continuous structure 15, which substantially continuous structure 15 is electrically connected to the potential of the first load terminal 11 by means of an electrically conductive contact (such as a plug or the like) 159.

For example, with reference to fig. 18, the substantially continuous structure 15 may comprise a substantially continuous trench 155 extending into the semiconductor body 10 along the vertical direction Z, for example as far as the control trench 14 and the source trench 16, wherein said substantially continuous trench 155 may comprise a substantially continuous trench electrode 156 electrically connected to the potential of the first load terminal 11 and isolated from the semiconductor body by a trench insulator 157. For example, in fig. 17 and 18, reference numeral 159 designates an electrically conductive contact (e.g., a contact plug) that establishes an electrical connection between a substantially continuous structure (e.g., the substantially continuous trench electrode 156) and the first load terminal 11. These contacts 159 may be arranged in the region between the diode regions 1-22 and the IGBT regions 1-21, as illustrated in fig. 17. Each of the trench electrodes 156 may surround the respective diode region 1-22 continuously, i.e. without interruption.

In addition to or alternatively to the substantially continuous trench 155 surrounding the diode regions 1-22, referring to fig. 19, the substantially continuous structure 15 may comprise a semiconductor portion 151 of the second conductivity type. Said semiconductor portion 151 is electrically connected to the potential of the first load terminal 11 and may extend into both the diode regions 1-22 and the IGBT regions 1-21 it surrounds, for example so as to laterally overlap with at least one or more of the source trenches 14/control trenches 16 arranged in the vicinity of the diode regions 1-22 and/or so as to merge seamlessly with the body region 102 in both the diode regions 1-22 and the IGBT regions 1-21. For example, semiconductor portion 151 extends into a region between trench 155 and control trench 14 adjacent to diode regions 1-22. Still further, the semiconductor portions 151 of the second conductivity type may extend further along the vertical direction Z, or even further than the source trenches 14/control trenches 16, as compared to the body regions 102, and/or the semiconductor portions 151 of the second conductivity type may extend continuously, i.e. without interruption, to surround the respective diode regions 1-22.

The dopant concentration of semiconductor portion 151 may be in the range of 50% to 500% of the dopant concentration of body region 102 in IGBT zones 1-21.

Based on fig. 20 and 21, both schematically and exemplarily illustrating a horizontally projected section of an RC IGBT according to one or more embodiments, further optional features will be described.

For example, with reference to fig. 20, which corresponds to the embodiment of fig. 17, it may be ensured that each diode region 1-22 is laterally displaced from any semiconductor region of the first conductivity type electrically connected to the first load terminal 11 by a distance dxy of at least 4 μm or at least 6 μm or at least 10 μm. The semiconductor region of the first conductivity type may be, for example, a source region 101 schematically illustrated in fig. 20 on the basis of a plurality of lines extending in parallel along the first lateral direction X. That is, in an embodiment, each semiconductor region of the first conductivity type that is electrically connected to the first load terminal 11 (such as the source region 101) of the RC IGBT 1 is spatially displaced at least 4 μm away from each diode region 1-22. This alternative provision may also be provided without an intersecting trench structure and/or without a substantially continuous structure 15, in contrast to the schematic illustration in fig. 20.

In case the RC IGBT 1 is provided in a chip of considerable size, the active area of the RC IGBT 1 may comprise several active regions 1-2, for example quadrants A, B, C and D arranged separated from each other, wherein the control finger structure 132 is electrically connected to the potential of the control terminal 13. In each of these active regions 1-2, the design rules for positioning and sizing the diode sections 1-22 described above and other features related to the diode sections 1-22 and the IGBT sections 1-21 may apply. For example, in such a case, the outer portion of the control flow structure 131 (at least partially) surrounds the entire active area of the RC IGBT 1 including the four active regions 1-2A, 1-2B, 1-2C, and 1-2D, and the inner portion of the control flow structure 131 (also sometimes referred to as a control finger) intersects the active area such that each of the four active regions 1-2A, 1-2B, 1-2C, and 1-2D is partially surrounded by the control flow structure 131. That is, the control flow structure 131 extends along the course of the lateral perimeters 1-20A, 1-20B, 1-20C, and 1-20D of the four active regions 1-2A, 1-2B, 1-2C, and 1-2D (in the illustrated example, entirely along 1-20A and 1-20B and partially along 1-20C and 1-20D).

Due to the course of the control flow channel structure 131 exemplarily illustrated in fig. 21, the stripe-like configuration of the control trenches 14 in the active areas 1-2A and/or in the active areas 1-2B may be arranged perpendicular to the stripe-like configuration of the control trenches 14 in the active areas 1-2C and/or in the active areas 1-2D. More generally, the stripe configuration of trenches 14 (and trenches 16, if present) in one of active regions 1-2A-1-2D may be oriented differently, e.g., arranged vertically, as compared to the stripe configuration of trenches 14 (and trenches 16, if present) in another of active regions 1-2A-1-2D. However, the design rules for positioning and sizing the diode sections 1-22 described above and other features related to the diode sections 1-22 and the IGBT sections 1-21 will still apply to the active regions 1-2A and/or in the active regions 1-2B (the X-direction and the Y-direction are then interchanged, as will be clear to the person skilled in the art).

A method of processing the RC IGBT is also presented herein. An embodiment of a method includes forming the following components of an RC IGBT: an active region having an IGBT section and a plurality of at least three diode sections; an edge termination region surrounding the active region; a semiconductor body extending in both the active region and the edge termination region and having a front side and a back side, the semiconductor body having a thickness, the thickness being a distance from the front side to the back side in a vertical direction in one of the diode sections; a first load terminal and a control terminal, both at the front side of the semiconductor body, and a second load terminal at the back side of the semiconductor body. Each diode segment is configured to conduct a diode load current between a first load terminal and a second load terminal. The IGBT section is configured to conduct a forward load current between the second load terminal and the first load terminal. The control terminal is electrically connected to a conductive control flow channel structure arranged at the front side of the semiconductor body and extending at least partially along a course of the lateral perimeter of the active region. A plurality of control trenches are arranged parallel to each other along a first lateral direction, and each control trench extends into the semiconductor body along a vertical direction pointing from the front side to the back side. Each control trench has a stripe-like configuration extending along a second lateral direction from a respective first section of the lateral perimeter towards a respective second section of the lateral perimeter opposite the respective first section, wherein the first lateral direction is perpendicular to the second lateral direction. Each control trench houses an insulated control electrode configured to receive a control signal via the control runner structure for controlling the IGBT segments. The processing method includes obeying a design rule according to which: each control trench is interrupted no more than once by at most a single one of the diode segments along its respective extension in the second lateral direction. In the lateral region of the active region, the diode segments themselves do not overlap one another in the lateral direction and the horizontal projections of the diode segments do not overlap one another in the lateral direction along the second lateral direction either. Within a lateral region of the active region, horizontal projections of the at least two diode segments along the first lateral direction do not overlap each other.

Exemplary embodiments of the method correspond to the embodiments of the RC IGBT 1 described above.

Embodiments related to the RC IGBT and the corresponding processing method are explained above. According to at least some of these embodiments, the following designs are proposed: it produces a quasi-gate (control electrode) independent diode characteristic while achieving a low ohmic connection between the control electrode and the control runner structure in the IGBT section and a low thermal resistance for the diode section. Further, the embodiments additionally enable a reduced turn-on overvoltage of the diode section.

Embodiments related to power semiconductor devices such as RC IGBTs and corresponding processing methods are explained above. These power semiconductor devices are based on silicon (Si), for example. Thus, a single-crystal semiconductor region or layer, such as the semiconductor body 10 and regions/zones thereof (e.g., regions, etc.), may be a single-crystal Si region or layer. In other embodiments, polysilicon or amorphous silicon may be used.

It should be understood, however, that the semiconductor body 10 and its regions/zones may be made of any semiconductor material suitable for the manufacture of semiconductor devices. Examples of such materials include, but are not limited to, elemental semiconductor materials such as silicon (Si) or germanium (Ge), group IV compound semiconductor materials such as silicon carbide (SiC) or silicon germanium (SiGe), binary, ternary, or quaternary III-V semiconductor materials such as gallium nitride (GaN), gallium arsenide (GaAs), gallium phosphide (GaP), indium phosphide (InP), indium gallium phosphide (InGaPa), aluminum gallium nitride (AlGaN), aluminum indium nitride (AlInN), indium gallium nitride (InGaN), aluminum gallium indium nitride (AlGaInN), or indium gallium arsenide phosphide (InGaAsP), and binary or ternary II-VI semiconductor materials such as cadmium telluride (CdTe) and mercury cadmium telluride (HgCdTe), to name a few. The above-mentioned semiconductor materials are also referred to as "homojunction semiconductor materials". When two different semiconductor materials are combined, a heterojunction semiconductor material is formed. Examples of heterojunction semiconductor materials include, but are not limited to, aluminum gallium nitride (AlGaN) -aluminum gallium indium nitride (AlGaInN), indium gallium nitride (InGaN) -aluminum indium gallium nitride (AlGaInN), indium gallium nitride (InGaN) -gallium nitride (GaN), aluminum gallium nitride (AlGaN) -gallium nitride (GaN), indium gallium nitride (InGaN) -aluminum gallium nitride (AlGaN), silicon-silicon carbide (SixC)₁-x) and a silicon-SiGe heterojunction semiconductor material. For power semiconductor switching applications, Si, SiC, G are currently predominantly usedaAs and GaN material.

Spatially relative terms, such as "below," "lower," "beneath," "above," and "upper," are used for ease of description to explain the positioning of one element relative to a second element. These terms are intended to encompass different orientations of the corresponding device in addition to different orientations than those depicted in the figures. Further, terms such as "first," "second," and the like, are also used to describe various elements, regions, sections, and the like, and are also not intended to be limiting. Like terms refer to like elements throughout the description.

As used herein, the terms "having," "including," "presenting," and the like are open-ended terms that indicate the presence of stated elements or features, but do not exclude additional elements or features.

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