Charge compensation semiconductor devices

Abstract

Field effect semiconductor device comprising: - a semiconductor body (40) having a first surface (101), an edge (41) defining the semiconductor body (40) in a direction substantially parallel to the first surface (101), an active region (110), and a peripheral region (120) disposed between the active region (110) and the edge (41); - a source metallization (10) arranged on the first surface (101); and - a drain metallization (11), wherein the semiconductor body (40) in the active region (110) further comprises: - a plurality of drift sections (1) of a first conductivity type alternating with compensation regions (6) of a second conductivity type, wherein the drift sections (1) comprise a first maximum doping concentration and are in ohmic contact with the drain metallization (11), and wherein the compensation regions (6) are in ohmic contact with the source metallization (10), wherein the semiconductor body (40) in the peripheral region (120) further comprises: - a second semiconductor region (2) in ohmic contact with the drift sections (1) and comprising a second maximum doping concentration of doping materials of the first conductivity type, wherein the second maximum doping concentration is lower by a factor of at least five than the first maximum doping concentration of the drift sections (1); - a first edge termination region (7, 17) of the second conductivity type in ohmic contact with the source metallization (10) and adjacent to the second semiconductor region (2); and - a second edge termination region (18) of the first conductivity type, comprising a fourth maximum doping concentration that is higher than the second maximum doping concentration, wherein the second edge termination region (18) is in ohmic contact with the drain metallization (11), adjoins the first edge termination region (17) and is arranged between the first edge termination region (17) and the first surface (101).

Description

TECHNICAL FIELD

[0001] Embodiments of the present invention relate to semiconductor devices having a charge compensation structure, in particular power semiconductor field effect transistors having a charge compensation structure and an edge termination structure. BACKGROUND

[0002] Semiconductor transistors, particularly field-effect controlled switching devices such as a metal-oxide-semiconductor field-effect transistor (MOSFET) or an insulated-gate bipolar transistor (IGBT), have been used for various applications, including, but not limited to, switches in power supplies and converters, electric vehicles, air conditioning systems, and even stereo systems. Particularly with regard to voltage devices capable of switching large currents and / or operating at high voltages, low on-state resistance Ron, high breakdown voltages U bd , high robustness and / or good softness are often desirable.

[0003] To achieve a low on-state resistance Ron and high breakdown voltages U bdTo achieve this, compensation semiconductor devices were developed. The compensation principle is based on the mutual compensation of charges in n- and p-doped regions in the drift zone of a vertical MOSFET, which are often referred to as n- or p-doped column regions.

[0004] Typically, the charge compensation structure formed by p-type and n-type regions is arranged beneath the actual MOSFET structure with its source, body and gate regions and also beneath the associated MOS channels, which are arranged side by side in the semiconductor volume of the semiconductor device or which are interleaved with each other in such a way that their charges can be mutually dissipated in the off-state and that in the activated state or the on-state an uninterrupted low-impedance conduction path is formed from a source electrode near the surface to a drain electrode arranged on the backside.

[0005] Due to the compensation of p-type and n-type doping, the doping of the current-carrying region can be significantly increased in the case of compensation components, resulting in a significant reduction in the on-state resistance Ron, despite the loss of a current-carrying region. The reduction in the on-state resistance Ron of such semiconductor voltage devices is associated with a reduction in the heat generated by the on-state current, so that such semiconductor voltage devices with charge compensation structures remain "cool" compared to conventional semiconductor voltage devices.

[0006] Switching losses of semiconductor voltage devices have become important. Depending on the device operation, the output charge Q OSS (or output capacitance C OSS ) and the switching losses E OSS, which are formed in the space charge region in the off-state or during a reverse voltage, the switching losses. The stored charge Q OSS of semiconductor devices with charge compensation structures can be comparatively high. This can lead to significant switching losses E OSS lead to important parts of the stored charge Q OSS at high voltages across the charge terminals of the semiconductor voltage device. To enable blocking, the output voltage Q OSS (at a certain blocking voltage) be completely removed, which leads to switching delays.

[0007] To achieve high breakdown voltages U bd To achieve this, an edge termination structure can be used in a peripheral region surrounding the active region with active MOSFET cells.

[0008] US 2007 / 0 272 979 A1 describes a semiconductor device comprising a semiconductor layer of a first conductivity type; a first semiconductor pillar region of the first conductivity type provided on a main surface of the semiconductor layer; a second semiconductor pillar region of a second conductivity type provided adjacent to the first semiconductor pillar region on the main surface of the semiconductor layer, wherein the second semiconductor pillar region together with the first semiconductor pillar region forms a periodic array structure that is substantially parallel to the main surface of the semiconductor layer; a first main electrode; a first semiconductor region of the second conductivity type; a second semiconductor region of the first conductivity type; a second main electrode; a control electrode;and a high-resistance semiconductor layer provided on the semiconductor layer in an edge termination portion surrounding the first semiconductor column region and the second semiconductor column region. The high-resistance semiconductor layer has a lower doping concentration than the first semiconductor column region. A boundary region is provided between a central region and the edge termination portion. The first semiconductor column region and the second semiconductor column region, which adjoin the high-resistance semiconductor layer in the boundary region, have a depth that gradually decreases toward the edge termination portion.

[0009] In addition, DE 10 2005 004 355 A1 describes a semiconductor device with a VLD (Variation of Lateral Doping) edge termination and DE 10 2006 023 598 B3 describes a semiconductor component with an active region and an edge region having a resurf semiconductor layer extending laterally outwards from the active region and laterally spaced-apart annular semiconductor regions embedded in the resurf semiconductor layer, each annular semiconductor region enclosing the active region.

[0010] However, the peripheral area requires chip area, thus increasing costs. Furthermore, the edge termination structure can significantly increase the output voltage Q OSS or the output capacitance C OSS contribute, e.g., to more than 10% of the total output capacity C OSS .

[0011] Accordingly, there is a need to improve semiconductor devices with charge compensation structures. SUMMARY

[0012] According to one embodiment of a field-effect semiconductor device, the field-effect semiconductor device comprises a semiconductor body having a first surface. The semiconductor body comprises an edge that delimits the semiconductor body in a direction substantially parallel to the first surface, an active region, and a peripheral region arranged between the active region and the edge. The field-effect semiconductor device further comprises a source metallization arranged on the first surface and a drain metallization. In the active region, the semiconductor body further comprises a plurality of drift sections of a first conductivity type alternating with compensation regions of a second conductivity type. The drift sections have a first maximum doping concentration and are in ohmic contact with the drain metallization.The compensation regions are in ohmic contact with the source metallization. In the peripheral region, the semiconductor body further comprises a first edge termination region and a second semiconductor region that is in ohmic contact with the drift sections and has a second maximum doping concentration of dopant materials of the first conductivity type that is at least five times lower than the second maximum doping concentration of the drift sections. The first edge termination region is of the second conductivity type, in ohmic contact with the source metallization, and is adjacent to the second semiconductor region.

[0013] According to one embodiment of a field-effect semiconductor device, the field-effect semiconductor device comprises a semiconductor body having a first surface. A source metallization is arranged on the first surface. The semiconductor body comprises an active region and a peripheral region surrounding the active region. In the active region, the semiconductor body further comprises a plurality of alternating n-type drift sections and p-type compensation regions. The drift sections have a first maximum doping concentration. The compensation regions are in ohmic contact with the source metallization.The semiconductor body further comprises an edge termination region and a second semiconductor region in ohmic contact with the drift sections, which extends into the peripheral area up to the first surface and has a second maximum doping concentration of n-type doping materials that is lower than the first maximum doping concentration. The edge termination region is in ohmic contact with the source metallization and borders the second semiconductor region. A concentration of p-type doping materials in the edge termination region varies in the perpendicular direction substantially orthogonal to the first surface.

[0014] According to one embodiment of a field-effect semiconductor device, the field-effect semiconductor device comprises a semiconductor body having a first surface. The semiconductor body comprises an edge that delimits the semiconductor body in a direction substantially parallel to the first surface, an active region, and a peripheral region arranged between the active region and the edge. The semiconductor device further comprises a source metallization arranged on the first surface and a drain metallization.In a vertical cross-section substantially orthogonal to the first surface, the semiconductor body further comprises: a plurality of alternating first n-type and first p-type column regions arranged in the active region; at least one second p-type column region arranged in the peripheral region; and at least one second n-type column region arranged between the at least one second p-type column region and the first p-type column regions. The first n-type column regions are in ohmic contact with the drain metallization. An integral doping concentration of the first n-type column regions is substantially equal to an integral doping concentration of the first p-type column regions. The first p-type column regions are in ohmic contact with the source metallization.The at least one second p-type column region is in ohmic contact with the source metallization and has an integral doping concentration that is lower than the integral doping concentration of the first p-type column regions divided by the number of first p-type column regions. The at least one second n-type column region has an integral doping concentration that is lower than the integral doping concentration of the first n-type column regions divided by the number of first n-type column regions.

[0015] Those skilled in the art will recognize additional features and advantages upon reading the following detailed description and upon viewing the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The components in the figures are not necessarily to scale, but rather the emphasis is on illustrating the principles of the invention. Furthermore, like reference numerals refer to similar parts throughout the figures. In the drawings: Fig. 1 shows a vertical cross section through a semiconductor body of a semiconductor device according to an embodiment; Fig. 2 a part of the vertical cross section through the semiconductor device shown in Fig. 1, according to one embodiment; Fig. 3 shows a vertical cross section through a semiconductor body of a semiconductor device according to an embodiment; Fig. 4 shows a vertical cross section through a semiconductor body of a semiconductor device according to an embodiment; Fig. 5 shows a vertical cross section through a semiconductor body of a semiconductor device according to an embodiment; Fig. 6 shows a vertical cross section through the semiconductor body of a semiconductor device according to an embodiment; and Fig. Figure 7 shows a horizontal cross section through the semiconductor body of the semiconductor device shown in Fig. 6, according to one embodiment. DETAILED DESCRIPTION

[0017] In the following detailed description, reference is made to the accompanying drawings, which form a part hereof, and in which is shown, for purposes of illustration, specific embodiments in which the invention may be practiced. In this regard, directional terminology such as "top", "bottom", "front", "back", "leading", "following", etc., will refer to the orientation of the figure(s) to be described. Since components of embodiments may be positioned in a variety of different orientations, the directional terminology is used for purposes of illustration and is not in any 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.

[0018] Reference will now be made in detail to the various embodiments, one or more examples of which are illustrated in the figures. Each example is provided for illustrative purposes and is not to be considered as limiting the invention. For example, features shown or described as part of one embodiment may be used in or in conjunction with other embodiments to obtain a further embodiment. It is intended that the present invention encompass such modifications and variations. The examples are described using specific language. The drawings are not to scale and are for illustration purposes only. For clarity, the same components or manufacturing steps have been given the same reference numerals in the different drawings unless otherwise indicated.

[0019] The term "horizontal," as used in this specification, is intended to refer to an orientation that is substantially parallel to a first or horizontal major surface of a semiconductor substrate or body. This may, for example, be the surface of a wafer or a mold.

[0020] The term "vertical," as used in this specification, is intended to describe an orientation that is substantially perpendicular to the first surface, i.e., parallel to the normal direction of the first surface of the semiconductor substrate or body. Similarly, the term "horizontal," as used in this specification, is intended to describe an orientation that is substantially parallel to the first surface.

[0021] In this description, a second surface of a semiconductor substrate of a semiconductor body is intended to be formed by the bottom or rear surface, while the first surface is intended to be formed by the top, front, or main surface of the semiconductor substrate. The terms "above" and "below," as used in this description, therefore describe relative positioning of one feature with respect to another feature, taking this orientation into account.

[0022] In this specification, n-doped is referred to as the first conductivity type, while p-doped is referred to as the second conductivity type. Alternatively, the semiconductor devices may be formed with opposite doping relationships, such that the first conductivity type may be p-doped and the second conductivity type may be n-doped. In addition, some figures indicate relative doping concentrations by indicating "" or "+" next to the doping type. For example, "n" indicates a doping concentration that is lower than the doping concentration of an "n" doping region, while an "n + “-doping region has a higher doping concentration than the “n”-doping region. However, a specification of the relative doping concentration does not mean that the doping regions with the same relative doping concentration must have the same doping concentration, unless otherwise stated. For example, two different n +-doping regions have different absolute doping concentrations. The same applies, for example, to an n + -doping and a p + -doping region.

[0023] Certain embodiments described in this specification include, but are not limited to, field-effect semiconductor devices, in particular field-effect compensation semiconductor devices and fabrication methods therefor. Within this specification, the terms "semiconductor device" and "semiconductor component" are used synonymously. The field-effect semiconductor device is typically a vertical semiconductor device, such as a vertical MOSFET with a source metallization and an insulated gate electrode disposed on the first surface and a drain metallization disposed on a second surface opposite the first surface. Typically, the field-effect semiconductor device is a semiconductor voltage device having an active region with a plurality of MOSFET cells for carrying and / or controlling a charging current.In addition, the semiconductor voltage device typically has a peripheral region with at least one edge termination structure that at least partially surrounds the active region when viewed from above.

[0024] The term "semiconductor voltage device," as used in this specification, is intended to describe a single-chip semiconductor device with high-voltage and / or high-current switching capabilities. In other words, semiconductor voltage devices are designed for high voltages, typically in the ampere range and / or at voltages greater than about 10 V or even greater than about 100 V or 500 V. Within this specification, the terms "semiconductor voltage device" and "semiconductor voltage component" are used interchangeably.

[0025] The term "edge termination structure," as used in this specification, is intended to describe a structure that provides a transition region in which the high electric fields around an active area of ​​the semiconductor device vary successively with the potential at or near the edge of the device and / or between a reference potential, such as a ground voltage and a high voltage, e.g., at the edge and / or at the back of the semiconductor device. The edge termination structure can, for example, reduce the field intensity around a termination region of a rectification terminal by distributing the electric field lines across the termination region.

[0026] The term "field effect," as used in this description, is intended to describe the electric field-mediated formation of a conductive "channel" of a first conductivity type and / or the control of the conductivity and / or the shape of the channel in a semiconductor region of a second conductivity type, typically a body region of the second conductivity type. Due to the field effect, a unipolar current path is formed through the channel region and / or controlled between a source region of the first conductivity type and a drift region of the first conductivity type. The drift region may be in contact with a drain region. The drift region and the drain region are in low ohmic contact with a drain electrode (drain metallization). The source region is in low ohmic contact with a source electrode (source metallization).In the context of this description, the term "in ohmic contact" is intended to describe a low-ohmic current path between the respective components or sections of a semiconductor device when no voltages or only small sensing voltages are applied to and / or across the semiconductor device. Within this description, the terms "in ohmic contact," "in ohmic electrical contact," "electrically connected," and "in ohmic electrical connection" are used synonymously.

[0027] In the context of this description, the term "MOS" (metal oxide semiconductor) should be understood to include the more general term "MIS" (metal insulator semiconductor). For example, the term MOSFET (metal oxide semiconductor field-effect transistor) should be understood to include FETs with a gate insulator that is not an oxide, i.e., the term MOSFET is used according to its more general meaning of an IGFET (insulated gate field-effect transistor) or a MISFET (metal insulator semiconductor field-effect transistor). The term "metal" for the gate material of the MOSFET should be understood to include electrically conductive materials, e.g., metals, alloys, doped polycrystalline semiconductors, and metal semiconductor compounds such as metal silicides.

[0028] In the context of the present description, the term “gate electrode” is intended to describe an electrode that is adjacent to and isolated from the body region and is configured to form and / or control a channel region through the body region.

[0029] In the context of the present description, the term "field electrode" is intended to describe an electrode disposed adjacent to a semiconductor region, typically the drift region, partially isolated from the semiconductor region, and configured to extend a consumed portion in the semiconductor region by charging to an appropriate voltage, typically a negative voltage with respect to the surrounding semiconductor region for an n-type semiconductor region.

[0030] In the context of the present description, the term “mesa” or “mesa region” is intended to describe a semiconductor region between two adjacent trenches that extend into the semiconductor substrate or body in a vertical cross-section.

[0031] The term "commutate" as used in this specification is intended to describe the switching of the current of a semiconductor device from a conducting direction, in which a pn charge junction, e.g., the pn junction between the body region and the drift region of a MOSFET, is forward biased, to the opposite or blocking direction, in which the pn charge junction is reverse biased. The term "fast commutation" as used in this specification is intended to describe commutation at a speed of at least about 10 9 V / s, more typically at a speed of at least about 5*10 9 V / s, describe.

[0032] In the following, embodiments relating to semiconductor devices (semiconductor components) and manufacturing methods for forming semiconductor devices are explained primarily with reference to silicon (Si) semiconductor devices. Accordingly, a monocrystalline semiconductor region or layer is typically a monocrystalline Si region or Si layer. However, it should be understood that the semiconductor body may be made of any other material suitable for fabricating a semiconductor device.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 just a few. to name a few. The semiconductor materials mentioned above are also called homojunction semiconductor materials. When two different semiconductor materials are combined, they form a heterojunction semiconductor.Examples of heterojunction semiconductor materials include, but are not limited to, aluminum gallium nitride (AlGaN), aluminum gallium indium nitride (AlGaInN), indium gallium nitride (InGaN), aluminum gallium indium nitride (AlGaInN), indium gallium nitride (InGaN), gallium nitride (GaN), aluminum gallium nitride (AlGaN), gallium nitride (GaN), indium gallium nitride (InGaN), aluminum gallium nitride (AlGaN), silicon silicon carbide (Si. x C 1-x ) and silicon-SiGe heterojunction semiconductor materials. Currently, Si, SiC, GaAs, and GaN materials are mainly used for semiconductor voltage applications. If the semiconductor body comprises a wide bandgap material such as SiC or GaN, which exhibits a high breakdown field strength or a high critical avalanche field strength, respectively, the doping of the respective semiconductor regions can be selected to be higher, which reduces the on-state resistance Ron, which is also referred to as the on-resistance Ron.

[0033] With reference to Fig. 1, a first embodiment of a semiconductor device 100 is explained. Fig. 1 shows a vertical cross-section through a semiconductor body 40 of the semiconductor device 100. The semiconductor body 40 extends between a first surface 101, which faces in a vertical direction, and a second surface 102, which is arranged opposite the first surface 101. In a horizontal direction, which is substantially parallel to the first surface 101, the semiconductor body 40 is delimited by an edge 41, e.g., a saw edge. The semiconductor body has an active region 110 and a peripheral region 120, which is arranged between the active region and the edge 41. Typically, the peripheral region 120 surrounds the active region 110 when viewed from above.

[0034] A source metallization 10 is arranged on the first surface 101. A drain metallization 11 is arranged on the second surface 102, i.e., opposite the source metallization 10. In addition, a gate electrode 12 is typically also arranged on the first surface 101 and is insulated from the source metallization 10 and the semiconductor body 40 by a dielectric region 13. The gate electrode 12 is connected to a gate metallization that is not in Fig. 1. Accordingly, the semiconductor device 100 can be operated as a 3-terminal device.

[0035] The semiconductor body 40 typically comprises a monocrystalline bulk material 4 and at least one epitaxial layer 3, 2, 1 formed thereon. The use of the epitaxial layer(s) 3, 2, 1 provides greater freedom in adjusting the background doping of the material, since the doping concentration can be adjusted during deposition on the epitaxial layer(s).

[0036] In the Fig. 1, the semiconductor body 40 comprises a highly doped n-type drain region 4 extending to the second surface 102 and in ohmic contact with the drain metallization 11 and with an n-type field stop region 3 adjacent to the drain region 4 and having a lower maximum doping concentration than the drain region 4. The drain region 4 and the optional field stop region 3 are typically arranged in the active area 110 and in the peripheral area 120 and may extend to the edge 41.

[0037] In the active region 110, a plurality of alternating n-type drift sections 1 and p-type compensation regions 6, which together form the respective pn junctions, are arranged. The drift sections 1 have a first maximum doping concentration, which is typically higher than the maximum doping concentration of the field stop region 3. The drift sections 1 are in ohmic contact with the drain metallization 11 (in the exemplary embodiment via the adjacent field stop region 3 and the drain region 4) and typically extend to the first surface 101. For greater clarity, Fig. 1 only three drift sections 1 and two compensation regions 6 are shown.

[0038] A (mathematically) integrated doping concentration of the drift sections 1 (integral doping concentration) is essentially the same as an integrated doping concentration (integral doping concentration) of the compensation regions 6. Accordingly, the drift regions 1 and the compensation regions 6 form a pn compensation structure 1, 6. The average doping concentration of the drift sections 1 and the compensation regions 6, i.e., the mathematically integrated difference of the donor concentration and the acceptor concentration per volume, is typically less than the maximum doping concentration of the field stop region 3, even more typically less than the average doping concentration of the field stop region 3. Even more typically, the average doping concentration of the drift sections 1 and the compensation regions 6 is less than 10% or less than 5% of the maximum doping concentration of the drift sections 1 and / or the compensation regions 6.Even more typically, the average doping concentration of the drift sections 1 and the compensation regions 6 is essentially zero.

[0039] In the exemplary embodiment, the p-type compensation regions 6 are formed as vertically aligned pillars. Alternatively, the p-type compensation regions 6 are formed as substantially vertically aligned strip-like parallelepipeds, rectangles, or ellipsoids. Hereinafter, the n-type drift sections 1 and the p-type compensation regions 6 are also referred to as n-type pillar regions 1 and p-type pillar regions 6.

[0040] Depending on the fabrication of the pn compensation structure 1, 6, the doping concentration in the drift sections 1 and / or in the compensation regions 6 may vary. This is in Fig. 1 by the dashed ellipses, which indicate that the concentration of p-type doping materials is higher in the center of the four exemplary bubble-shaped sections of each of the compensation regions 6. The compensation regions 6 are in ohmic contact with the source metallization 10.

[0041] This is explained in more detail with reference to Fig. 2, which shows an enlarged upper portion of the semiconductor device 100 shown in Fig. 1 is shown. The Fig. 2 typically corresponds to an upper part of one of a plurality of unit cells 111 in the active region 110 of the semiconductor device 100.

[0042] In the exemplary embodiment, a body contact region of the p + -Type 5c and two source regions of n + -type 15 in a body region of p-type 5. Furthermore, an optional contact region extends from the p +-Type 6c between the body contact region 5c and the compensation region 6. The body contact region(s) 5c and the contact region(s) 6c are not shown for clarity. Fig. 1 and the following figures.

[0043] A portion 13a of the dielectric region 13 is disposed between the first surface 101 and each of the gate electrodes 12 and extends horizontally from the drift portion 1 along the body region 5 to at least the source region 15, such that an inversion channel, also referred to herein as a MOS channel, is formed by the field effect in a channel region of the body region 5 along the portion(s) 13a forming a gate dielectric region. Accordingly, the semiconductor device 100 can be operated like a MOSFET.

[0044] The remaining portion of the dielectric region 13 forms an interlayer dielectric between the source metallization 10 and the gate electrode 12, respectively, and the first surface 101.

[0045] In the exemplary embodiment, the source metallization 10 is in electrical contact with the source regions 15 and the body contact region 5c via a shallow trench contact formed through the interlayer dielectric 13 and into the semiconductor body 40. In other embodiments, the source metallization 10 is in electrical contact with the source region 15 and the body contact region 5c substantially at the first surface 101.

[0046] According to another embodiment, the gate electrode(s) 12 and the gate dielectric(s) 13a may be formed in a respective trench extending from the first surface 101 into the semiconductor body 40. In this embodiment, the body region 5 and the source regions 15 are adjacent to an upper part of the respective trench, while the drift sections I are adjacent to a lower part of the respective trench. In this embodiment, the drift sections I may not extend to the first surface 101 in the active area 110. With reference to Fig. 1 further embodiments are explained.

[0047] According to one embodiment, the doping concentrations of the p-type compensation regions 6 and the drift sections 1 are selected such that their charges can be mutually consumed in the off-state and that, in the on-state, an uninterrupted, low-ohmic conduction path is formed from the source metallization 10 to the drain metallization 11.

[0048] As in Fig. 1, the interlayer dielectric 13 typically also covers the semiconductor body 40 in the peripheral region 120. The interlayer dielectric 13 may extend substantially to the edge 41.

[0049] In the exemplary embodiment, drift portion 1, which is closest to edge 41, does not contribute or significantly contribute to the forward current of MOSFET 100 and is therefore not attributed to active region 110. Active region 110 may be defined by the presence of source regions 15 and insulated gate electrodes 12.

[0050] According to one embodiment, the semiconductor body 40 further comprises a p-type edge termination region 7 in ohmic contact with the source metallization 10 (e.g., via a horizontal extension portion of the body region 5') and a second semiconductor region 2 in ohmic contact with the drift portions 1, which extends into the peripheral area 120 up to the first surface 101 and which has a second maximum doping concentration of n-type dopants that is lower than the first maximum doping concentration of the drift portions 1 and is typically lower than the maximum doping concentration of the field stop region 3. The p-type edge termination region 7 is adjacent to the second semiconductor region 2 and has a concentration of p-type dopants that varies in the vertical direction.

[0051] The second maximum doping concentration of n-type doping materials is typically lower than the first maximum doping concentration by a factor of at least five, more typically by a factor of at least about 10, even more typically by a factor of at least about 20, even more typically by a factor of at least about 50, e.g., by a factor of about 100. The second semiconductor region 2 may be an n-type semiconductor region forming a pn junction with the edge termination region 7. The second semiconductor region 2 may also be a substantially intrinsic semiconductor region.

[0052] Accordingly, the compensation MOSFET 100 is provided with an edge termination that requires a smaller chip area, such as an edge termination without source regions, and is based on alternating n-type and p-type column regions with a lower slope than used in the active region.

[0053] The second semiconductor region 2 and the edge termination region 7 typically surround the active area 110 when viewed from above.

[0054] Furthermore, the second semiconductor region 2 can extend into the active region 110. For example, the second semiconductor region 2 can be arranged in the active region 110 between the field stop region 3 and the compensation structure 1, 6.

[0055] Typically, the concentration of the p-type dopants is highest at or at least near the first surface 101. The vertical concentration profile of the p-type dopants can be selected in the horizontal direction, similar to a VLD (variation of lateral doping) edge termination structure.

[0056] In other embodiments, the concentration of p-type dopants is highest at a vertical depth in a range of about 20% to about 50% of the vertical extent of the edge termination region 7. For example, the concentration of p-type dopants may be highest at about one-third of the vertical extent of the edge termination region 7.

[0057] The edge termination region 7 typically extends from the first surface 101 into the second semiconductor region 2 to a depth corresponding to at least about 30% of the depth of the compensation regions 6, more typically at least about 50% of the depth of the compensation regions 6. The edge termination region 7 may extend even deeper into the semiconductor body 40 than the compensation regions 6.

[0058] The (mathematically) vertically integrated concentration of the p-type doping materials of the edge termination region 7 is typically lower compared to the compensation regions 6 and can be in a range of about 5 × 10 11 cm -2 up to about 5 × 10 12 cm -2 The maximum horizontal extent of the edge termination region 7 is typically in a range of approximately 2 µm to approximately 20 µm and may vary in a perpendicular direction from the first surface 101. In other embodiments, the maximum horizontal extent of the edge termination region 7 may occur away from the first surface 101.

[0059] Due to the edge termination region 7, the loading of the unit cells of the active area 110 adjacent to the edge 41 in the off-state (blocking mode) can be significantly reduced, since the edge termination region 7, with a sufficiently high integrated doping concentration, is only degraded at a higher reverse voltage. Accordingly, the reduction of the output capacitance C OSS delayed and thus the switching smoothness is improved.

[0060] Due to the vertically varying concentration of p-type doping materials of the edge termination region 7, the maximum of the electric field in the off-state typically occurs inside the semiconductor body 40 and not at its first surface 101. Accordingly, the effect of surface changes at or on the first surface on the blocking capability is reduced.

[0061] Furthermore, high avalanche stability can be achieved due to the vertically varying concentration of p-type doping materials of the edge termination region 7.

[0062] Furthermore, the semiconductor device 100 may be provided with two or even more edge termination regions 7 having a vertically varying concentration of p-type doping materials. The vertical and / or horizontal extent of the at least two edge termination regions 7 may be substantially identical or may differ.

[0063] Furthermore, the edge termination region 7 and the compensation structure 1, 6 can be formed in common manufacturing processes. For example, several alternating epitaxial depositions and masked p-implantations, followed by a common drive-in, can be used to form the compensation structure 1, 6. To produce the edge termination region 7 in parallel, only additional openings of the implantation masks used in the peripheral area 120 are required. This is possible because the (relative) difference in the integrated doping concentration between the compensation regions 6 and the edge termination region 7 can be determined by the areas of the openings in the implantation mask. In other embodiments, the edge termination structure 7 and the compensation structure 1, 6 can be formed in common manufacturing processes by filling trenches of different widths and depths with p-doped semiconductor material, e.g.using an epitaxial deposition of semiconductor material.

[0064] As in Fig. 1, the concentration of p-type doping materials in a vertical cross section may be substantially mirror-symmetric with respect to a central vertical axis of the edge termination region 7, as indicated by the dashed lines in the edge termination region 7 corresponding to equi-concentration lines.

[0065] Fig. 3 shows a vertical cross section through a field effect semiconductor device 200. The semiconductor device 200 is the one described above with reference to Fig. 1 and Fig. 2. However, the concentration of p-type doping materials of the edge termination region 7 of semiconductor device 200 in the vertical cross section is not mirror-symmetric. In the Fig. 3, the concentration of p-type doping materials along at least one horizontal line crossing the edge termination region 7 or in at least one horizontal cross-section has a maximum value and a steeper gradient toward the active area 110 compared to the opposite direction. Accordingly, the edge termination region 7, and thus the peripheral area 120 of the semiconductor device 200, may have an even smaller horizontal extent, resulting in even further reduced device costs. The dashed-dotted line in Fig. 3 corresponds to the inner interface between the edge termination region 7 and the second semiconductor region or the body region 5 in Fig. 1.

[0066] The non-mirror-symmetric edge termination region 7 can be manufactured in a similar manner to a mirror-symmetric one, using an implantation mask which is slotted in the peripheral area 120 in a suitable manner.

[0067] Fig. 4 shows a vertical cross section through a field effect semiconductor device 300. The semiconductor device 300 is similar to the one described above with reference to Fig. 1 and Fig. 2. However, the semiconductor body 40 of the semiconductor device 200 further comprises an n-type channel stop region 8, which is adjacent to the second semiconductor region 2 and has a maximum doping concentration higher than the second maximum doping concentration of the second semiconductor region 2. Typically, the channel stop region 8 extends to the first surface 101 and is arranged between the edge 41 and the edge termination region 7. The channel stop region 8 may extend substantially to the edge 41. In other embodiments, the channel stop region 8 may extend in a vertical direction from the first surface 101 to the field stop region 3 or even to the drain region 4.

[0068] Due to the channel stop region 8, the electric field in the off-state does not extend, or at least almost does not extend, to the edge 41. Accordingly, a low leakage current is ensured, since crystal defects that could occur due to sawing are prevented by the highly doped channel stop region 8.

[0069] Fig. 5 shows a vertical cross section through a field effect semiconductor device 400. The semiconductor device 400 is similar to the one described above with reference to Fig. 4. However, two exemplary floating n-type semiconductor regions 9 are fully embedded within the edge termination region 7 of semiconductor device 400. The one or more of the floating n-type semiconductor regions 9 are typically arranged within the edge termination region 7 such that a space charge region formed during the off-state reaches the respective pn junction formed with the edge termination region 7.

[0070] The doping concentration of the one or more of the floating n-type semiconductor regions 9 may be in a range of about 10 15 cm -3 up to about 10 17 cm -3Accordingly, avalanche multiplication in the space-charge region at the pn junctions within the edge termination region 7 can occur even at a comparatively low reverse bias. The resulting hole current typically improves softness during fast commutation.

[0071] Fig. Figure 6 shows a vertical cross section through a field effector semiconductor device 500. The active region 110 of the field effect semiconductor device 500 is similar to the active region of the semiconductor device 100 described above with reference to Fig. 1 and Fig. 2 and also includes a compensation structure formed by a plurality of alternating first n-type pillar regions (drift sections) 1 and first p-type pillar regions (compensation regions) 6. The first p-type pillar regions 6 are in ohmic contact with the source metallization 10, and the first n-type pillar regions 1 are in ohmic contact with the drain metallization 11 arranged opposite. An integrated doping concentration of the first n-type pillar regions 1 is substantially equal to an integrated doping concentration of the first p-type pillar regions 6. The dashed ellipses within the first n-type pillar regions 1 and the first p-type pillar regions 6 indicate optional subregions with a higher concentration of n-type doping materials and with a higher concentration of p-type doping materials, respectively.

[0072] However, the semiconductor body 40 of the semiconductor device 500 further comprises a second p-type pillar region 6' in ohmic contact with the source metallization 10 and a second n-type pillar region 1' arranged between the second p-type pillar region 6' and the outermost first p-type pillar regions 6', thus forming respective pn junctions. The dashed ellipses within the second n-type pillar regions 1' and the second p-type pillar regions 6' indicate optional subregions with a higher concentration of n-type doping materials and a higher concentration of p-type doping materials, respectively. The second p-type pillar region 6' is arranged in the peripheral area 120 and has an integrated doping concentration that is lower than the integrated doping concentration of the first p-type pillar regions 6 divided by the number of first p-type pillar regions 6.The second n-type pillar region 1' has an integrated doping concentration that is lower than the integrated doping concentration of the first n-type pillar regions 1 divided by the number of first n-type pillar regions 1. The second n-type pillar region 1' may or may not contribute to the forward current. Accordingly, the gate electrode 12, which is arranged above the second n-type pillar region 1', is only optional. Depending on its contribution to the forward current, the second n-type pillar region 1' is allocated to the active region 110 or the peripheral region 120, respectively. The body region 5', which is arranged between the second p-type pillar region 6' and the source metallization 10, comprises no source region or comprises a source region surrounded by a sufficient amount of p-dopants to prevent the formation of an electron channel and is therefore arranged in the peripheral region 120.The second n-type pillar region 1' and the second p-type pillar region 6' can also be considered as forming a transition region or zone between the active region 110 and the peripheral region 120.

[0073] Due to the reduced doping of the second n-type pillar region 1' and the second p-type pillar region 6' compared to the compensation structure 1, 6, the potential drop across the second n-type pillar region 1' and the second p-type pillar region 6' during the off-state (blocking mode) is also lower. Accordingly, any avalanche breakdown is expected to occur only in the active region 110. Due to the larger area of ​​the active region 110 compared to the peripheral region 120, the semiconductor device 500 tolerates higher avalanche currents or avalanche energies without damaging the device.

[0074] In applications with infrequent or no avalanche events, such as in resonant circuits, the transition region can be omitted to further reduce the area of ​​the peripheral region 120.

[0075] In the peripheral region 120, the semiconductor body 40 comprises the following: a second n-type semiconductor region 2, which is adjacent to the second p-type column region 6' and which has a second maximum doping concentration that is lower than a first maximum doping concentration of the second n-type column region 1'; a first p-type edge termination region 17, which is adjacent to the second semiconductor region 2; and a second n-type edge termination region 18. The second maximum doping concentration of the first n-type column regions is typically lower than a first maximum doping concentration of the first n-type column regions 1 by a factor of at least five, more typically by at least a factor of ten, e.g., by a factor of about 50 or about 100. Due to the low concentration of n-type dopants in the second semiconductor region 2, the contribution of the second semiconductor region 2 to the total output charge Q OSSvery low.

[0076] The second n-type edge termination region 18 has a fourth maximum doping concentration that is higher than the second maximum doping concentration, is adjacent to the first edge termination region 17, and is at least partially disposed between the first edge termination region 17 and the first surface 101. Typically, a vertically integrated doping concentration of the second n-type edge termination region 18 is equal to or less than a vertically integrated doping concentration of the second p-type edge termination region 17.

[0077] The initial charge Q OSSof the peripheral region 120 is mainly determined by the second n-type edge termination region 18, the first p-type edge termination region 17, and the second p-type pillar region 6', but is significantly lower than for edge termination structures based on a compensated inactive alternation of n-type and p-type pillar regions extending into the peripheral region 120.

[0078] In the Fig. 6, the first p-type edge termination region 17 is in ohmic contact with the source metallization 10.

[0079] In another embodiment, the first edge termination region 17 is a floating semiconductor region. In this embodiment, the semiconductor device 500 is typically designed such that a space charge region extending from the pn junction formed between the second n-type semiconductor region 2 and the second p-type column region 6' reaches the first edge termination region 17, or the pn junction formed between the second n-type semiconductor region 2 and the first edge termination region 17, even at a low reverse voltage of, for example, a maximum of 5% or 10% of the nominal blocking voltage.

[0080] The first edge termination region 17 typically acts as a JTE (junction termination extension) region and is also referred to as JTE region 17. The p-type doping concentration in the JTE region 17 may be constant or may decrease gradually or in small steps with decreasing distance from the edge 41. The latter is in Fig. 6 by the two sections 17a, 17b of the JTE region 17. Accordingly, the n-type doping concentration in the second n-type edge termination region 18 may be constant or may decrease gradually or in small steps with decreasing distance from the edge 41. The latter is shown in Fig. 6 by the two sections 18a, 18b of the second n-type edge termination region 18. The second n-type edge termination region 18 stabilizes the edge termination structure against surface variations on the first surface 101 and reduces the punching of holes in the dielectric region 13.

[0081] Furthermore, and as similarly as above with reference to Fig. As explained in Figure 4, an n-type channel stop region 8 having a third maximum doping concentration higher than the second maximum doping concentration is located adjacent to the second semiconductor region 2 and may extend to the edge 41 to reduce the leakage current. In other embodiments, the channel stop region 8 may extend in a vertical direction from the first surface 101 to the field stop region 3 or even to the drain region 4.

[0082] In the Fig. 6, the semiconductor device 500 further comprises a field plate 12a in ohmic contact with the gate electrodes 12 or a gate metallization (not shown). Fig. 6) and a field plate 11a in ohmic contact with the drain metallization 12. Accordingly, the distribution of the electric field in the off-state can be further balanced and / or the sensitivity of the semiconductor device 500 with respect to mobile charges in the dielectric region 13 can be further reduced.

[0083] The field plate 11a is typically arranged close to the edge 41. The field plate 11a is typically arranged between the field plate 12a and the source metallization 10.

[0084] The field plate 11a and / or the field plate 12a can be arranged as shown in Fig. 6, ie the vertical (minimum) distance of the field plates 11a and / or 12a from the first surface 101 can change gradually in a substantially horizontal direction. The number of steps can be increased compared to the Fig. 6, can also be larger or smaller. In other embodiments, only one or even no field plate 11a, 12a is arranged on the first surface 101.

[0085] Fig. Fig. 7 shows an edge section of a horizontal cross section through the semiconductor body 40 of the Fig. 6, below the JTE region 17. Typically, the active region 110, when viewed from above, is surrounded by a continuous channel stop region 8. The boundary between the active region 110 and the peripheral region 120 is shown in Fig. 7 are indicated by dashed lines. For clarity, only four first p-type pillar regions 6 of the active area 110 are shown in Fig. 7 shown. Fig. 6 typically corresponds to a cross-section along line 501, which defines an x-direction. As in Fig. As shown in Figure 7, the first p-type pillar regions 6 and the first n-type pillar regions 1 are typically adjacent to the second p-type pillar regions 6'. In this embodiment, the active region 110 is typically surrounded by a continuous second p-type pillar region 6' when viewed from above.

[0086] The minimum distance d y in the y-direction (extension direction of the regions 1, 1', 6 in horizontal cross sections) between the second semiconductor region 2 and the first n-type column regions 1 or the first p-type column regions 6 can be equal to, but also smaller than, the maximum distance in the x-direction d y of about 20 µm, between the second n-type column region 1' and the second semiconductor region 2. For example, the ratio d y / d x be smaller than about 0.8 or even 0.5. Typically, the minimum distance d yin the y-direction between the second semiconductor region 2 and the first n-type column regions 1 is substantially the same as the minimum distance in the y-direction between the second semiconductor region 2 and the second n-type column regions 1'.

[0087] In another embodiment, the first and second n-type column regions 1, 1' extend in the y-direction at least as far as the second semiconductor region 2. This is shown in Fig. 7 by the dashed-dotted curves. In this embodiment, the first p-type pillar regions 6 are typically adjacent to the second semiconductor region 2, and the second p-type pillar region 6' is not adjacent to the first p-type pillar regions 6. It should be noted that the electrical potential drop during the blocking mode of the semiconductor device 500 is typically different for the x-direction and the y-direction due to the geometry and arrangement of the pillar regions 1, 6 in the active region 110. The peripheral region 120 can be formed accordingly.

[0088] Furthermore, the first and second n-type column regions 1, 1' may have a reduced and / or decreasing extension in the x-direction near the second semiconductor region 2.

[0089] Furthermore, the concentration of doping materials is typically reduced in the y-direction, near and towards the second semiconductor region 2.

[0090] Again with regard to Fig. 6, further embodiments are explained. Typically, the integrated absolute doping concentration of the second p-type pillar region 6' is less than the integrated absolute doping concentration of the second n-type pillar region 1', which is less than the integrated absolute doping concentration of the first p-type pillar regions 6, which is substantially equal to the integrated absolute doping concentration of the first n-type pillar region 1.

[0091] Typically, the integrated concentration of p-type dopants in the second p-type pillar region 6' is lower by a factor of about 2 than the integrated concentration of n-type dopants in the second n-type pillar region 1'.

[0092] The integrated doping concentration of the second n-type pillar region 1' is typically in a range of about 50% to about 99% of the integrated doping concentration of the first n-type pillar region 1.

[0093] The integrated doping concentration of the second p-type 6' pillar region is typically in a range of about 25% to about 60% of the integrated doping concentration of the first p-type 6' pillar region.

[0094] In further embodiments, more than one pair of second pillar regions 1', 6' is used, typically with decreasing integrated doping concentrations toward the edge. In further embodiments, the integrated doping concentrations of the p-type second pillar regions 6' and the n-type second pillar regions 1' decrease with increasing distance from the active area 110 in a lateral direction.

[0095] According to numerical simulations of the semiconductor device 500, which are Fig. 6, the ripple of the electric potential in the second p-type column region 6' is reduced compared to the first column regions 1, 6. Accordingly, avalanche multiplication occurs only in the active region 110, as confirmed by analyzing the corresponding carrier production. According to the simulations, the horizontal extent of the peripheral region 120 of the semiconductor device 500 could be reduced even further. This would result in an even smaller product of R on times Q OSS lead.

[0096] The field-effect semiconductor device 500 may also be embodied as a semiconductor device 500 having a semiconductor body 40, including a first surface 101, an edge 41 that delimits the semiconductor body 40 in a direction substantially parallel to the first surface 101, an active region 110, and a peripheral region 120 disposed between the active region 110 and the edge 41. A source metallization 10 is disposed on the first surface, and a drain metallization 11 is disposed opposite the source metallization 10. In the active region 110, the semiconductor body 40 further comprises a plurality of alternating n-type drift sections 1 and p-type compensation regions 6, wherein the drift sections 1 have a first maximum doping concentration and are in ohmic contact with the drain metallization 11. The compensation regions 6 are in ohmic contact with the source metallization 10.The semiconductor body 40 further comprises a second semiconductor region 2 in ohmic contact with the drain metallization 11 and having a second maximum doping concentration of doping materials of the first conductivity type that is lower than the first maximum doping concentration. In the peripheral area 120, the semiconductor body 40 further comprises: a first p-type edge termination region 17 adjacent to the second semiconductor region 2; and a second n-type edge termination region 18 having a fourth maximum doping concentration that is higher than the second maximum doping concentration, adjacent to the first edge termination region 17, and at least partially arranged between the first edge termination region 17 and the first surface 101.

[0097] The field-effect semiconductor devices explained above with reference to the above figures have in common that they comprise a semiconductor body 40 having a first surface 101, an edge 41 that delimits the semiconductor body 40 in a direction substantially parallel to the first surface 101, an active region 110, and a peripheral region 120 arranged between the active region 110 and the edge 41. A source metallization 10 is arranged on the first surface 101, and a drain metallization 11 is arranged opposite the source metallization 10. In the active region 110, the semiconductor body 40 further comprises a plurality of drift sections 1 of a first conductivity type, alternating with compensation regions 6 of a second conductivity type. The drift sections 1 have a first maximum doping concentration and are in ohmic contact with the drain metallization 11.The compensation regions 6 are in ohmic contact with the source metallization 10. In the peripheral area 120, the semiconductor body 40 further comprises: a second semiconductor region 2 in ohmic contact with the drift sections 1 and having a second maximum doping concentration of doping materials that is lower by a factor of at least 5, more typically by a factor of at least 10, than the first maximum doping concentration of the drift sections 1; and a first edge termination region 7, 17 of the second conductivity type in ohmic contact with the source metallization 10 and adjacent to the second semiconductor region 2.

[0098] Typically, an integrated doping concentration of the drift sections 1 in the active region 110 is substantially the same as an integrated doping concentration of the compensation regions 6 in the active region 110.

[0099] The first edge termination region 7, 17 and the second semiconductor region 2 can form a pn junction.

[0100] Typically, the second maximum doping concentration is at least 50 times lower than the first maximum doping concentration.

[0101] According to one embodiment, the semiconductor body 40 further comprises in the peripheral region 120 a channel stop region 8 of the first conductivity type, which has a third maximum doping concentration that is higher than the second maximum doping concentration, is in ohmic contact with the second semiconductor region 2 and is arranged between the edge 41 and at least one of the first edge termination regions 7, 17 and the second semiconductor region 2.

[0102] According to one embodiment, the semiconductor body 40 further comprises a second edge termination region 18 of the first conductivity type having a fourth maximum doping concentration that is higher than a second maximum doping concentration in the peripheral region 120. The second edge termination region 18 is in ohmic contact with the drain metallization 11, is adjacent to the first edge termination region 17, and is arranged between the first edge termination region 17 and the first surface.

[0103] Typically, the second edge termination region 18 comprises a first portion 18a and a second portion 18b having a lower maximum doping concentration than the first portion 18a and disposed between the first portion 18a and the edge 41.

[0104] Similarly, the first edge termination region 17 typically comprises a first portion 17a and a second portion 17b having a lower integrated doping concentration than the first portion 17a and disposed between the first portion 17a and the edge 41.

[0105] According to one embodiment, a concentration of doping materials of the second conductivity type is varied in a vertical direction in the first edge termination region 7 such that the concentration is highest at least near the first surface 101.

[0106] At least one floating semiconductor region 9 of the first conductivity type can be completely embedded in the first edge termination region 7.

[0107] According to one embodiment, the semiconductor body 40 comprises in the peripheral region 120 a further compensation region 6' of the second conductivity type in ohmic contact with the source metallization 10, wherein the semiconductor body 40 further comprises a semiconductor section 1' forming a pn junction with the further compensation regions 6' and a further pn junction with one of the compensation regions 6, wherein an integrated doping concentration of the semiconductor section 1' is lower than the integrated doping concentration of the drift sections 1 divided by the number of drift sections 1, and wherein an integrated doping concentration of the further compensation region 6' is lower than the integrated doping concentration of the semiconductor section 1' and / or lower than the integrated doping concentration of the compensation regions 6 divided by the number of compensation regions.

[0108] According to one embodiment, the field effect semiconductor further comprises a dielectric region 13 arranged on the first surface 101, a field plate 11a arranged on the first surface 101 and in ohmic contact with the drain metallization 11 and / or a field plate 12a arranged on the first surface 101 and in ohmic contact with the gate metallization or the source metallization 10 arranged on the first surface 101.

[0109] Although various exemplary embodiments of the invention have been disclosed, it will be apparent to those skilled in the art that various changes and modifications may be made which achieve some of the advantages of the invention without departing from the spirit and scope of the invention. It will be apparent to those of ordinary skill in the art that other components having the same functions may be suitably substituted. It should be noted that features explained with reference to a particular figure may be combined with features of other figures, even in cases where this has not been expressly mentioned. Such modifications of the inventive concept are to be considered as covered by the appended claims.

[0110] Spatially related terms such as "beneath," "underneath," "below," "above," "above," and the like are used as a descriptive aid to explain the positioning of one element relative to a second element. These terms are intended to encompass different orientations of the device in addition to different embodiments than those illustrated in the figures. Furthermore, terms such as "first," "second," and the like are also used to refer to various elements, regions, sections, etc., and are not intended to be limiting. Similar terms refer to similar elements throughout the specification.

[0111] As used herein, the terms "having," "containing," "comprising," and the like are open-ended terms that indicate the presence of the specified elements or features, but do not exclude additional elements or features. The articles "a," "an," "an," and "the" are intended to include the plural as well as the singular, unless clearly contradicted by the context.

Claims

[1] A field-effect semiconductor device comprising: - a semiconductor body (40) having a first surface (101), an edge (41) defining the semiconductor body (40) in a direction substantially parallel to the first surface (101), an active region (110), and a peripheral region (120) disposed between the active region (110) and the edge (41); - a source metallization (10) arranged on the first surface (101); and - a drain metallization (11), wherein the semiconductor body (40) in the active region (110) further comprises: - a plurality of drift sections (1) of a first conductivity type alternating with compensation regions (6) of a second conductivity type, wherein the drift sections (1) comprise a first maximum doping concentration and are in ohmic contact with the drain metallization (11), and wherein the compensation regions (6) are in ohmic contact with the source metallization (10), wherein the semiconductor body (40) in the peripheral region (120) further comprises: - a second semiconductor region (2) in ohmic contact with the drift sections (1) and comprising a second maximum doping concentration of doping materials of the first conductivity type, wherein the second maximum doping concentration is lower by a factor of at least five than the first maximum doping concentration of the drift sections (1); - a first edge termination region (7, 17) of the second conductivity type in ohmic contact with the source metallization (10) and adjacent to the second semiconductor region (2); and - a second edge termination region (18) of the first conductivity type, comprising a fourth maximum doping concentration that is higher than the second maximum doping concentration, wherein the second edge termination region (18) is in ohmic contact with the drain metallization (11), adjoins the first edge termination region (17) and is arranged between the first edge termination region (17) and the first surface (101). [2] A field effect semiconductor device according to claim 1, wherein the second maximum doping concentration is lower than the first maximum doping concentration by a factor of at least ten. [3] A field effect semiconductor device according to claim 1 or 2, wherein the first edge termination region (7, 17) and the second semiconductor region (2) form a pn junction. [4] Field effect semiconductor device according to one of claims 1 to 3, wherein the semiconductor body (40) further comprises a channel stop region of the first conductivity type in the peripheral region (120) comprising a third maximum doping concentration that is higher than the second maximum doping concentration, the channel stop region being in ohmic contact with the second semiconductor region (2) and being arranged between the edge (41) and the first edge termination region (7, 17) and / or the second semiconductor region (2). [5] A field effect semiconductor device according to claim 4, wherein the second edge termination region (18) comprises a first portion (18a) and a second portion (18b) having a higher maximum doping concentration than the first portion (18a) and being disposed between the first portion (18a) and the edge (41). [6] A field effect semiconductor device according to any one of claims 1 to 5, wherein the first edge termination region (17) comprises a first portion (17a) and a second portion (17b) having a lower integral doping concentration than the first portion and is disposed between the first portion (17a) and the edge (41). [7] Field effect semiconductor device according to one of claims 1 to 6, wherein a concentration of dopant materials of the second conductivity type is varied in a vertical direction substantially orthogonal to the first surface (101) in the first edge termination region (7) and / or wherein the concentration is highest at and / or near the first surface (101). [8] A field effect semiconductor device according to any one of claims 1 to 7, wherein the semiconductor body (40) further comprises at least one floating semiconductor region (9) of the first conductivity type, the floating semiconductor region (9) being completely embedded in the first edge termination region (7). [9] A field effect semiconductor device according to any one of claims 1 to 8, wherein an integral doping concentration of the drift portions (1) in the active region (110) is substantially the same as an integral doping concentration of the compensation regions (6) in the active region (110). [10] Field-effect semiconductor device according to one of claims 1 to 9, wherein the semiconductor body (40) in the peripheral region (120) comprises a further compensation region (6') of the second conductivity type in ohmic contact with the source metallization (10), wherein the semiconductor body (40) comprises a semiconductor section (1') which forms a pn junction with the further compensation region (6') and one of the compensation regions (6), wherein an integral doping concentration of the semiconductor section (1') is lower than the integral doping concentration of the drift sections (1) divided by a number of the drift sections (1), and wherein an integral doping concentration of the further compensation region (6') is lower than the integral doping concentration of the semiconductor section (1') and / or lower than the integral doping concentration of the compensation regions (6) divided by a number of the compensation regions (6). [11] A field effect semiconductor device according to any one of claims 1 to 10, further comprising at least one of the following: - a dielectric region (13) arranged on the first surface (101); - a field plate (11a) arranged on the first surface (101) and in ohmic contact with the drain metallization (11); and - a field plate (12a) arranged on the first surface (101) and in ohmic contact with the source metallization (10) or with a gate metallization arranged on the first surface (101). [12] A field-effect semiconductor device comprising: - a semiconductor body (40) comprising a first surface (101), an active region (110) and a peripheral region (120) surrounding the active region (110); and - a source metallization (10) arranged on the first surface (101), wherein the semiconductor device (40) in the active region (110) further comprises: - a plurality of alternating n-type drift sections (1) and p-type compensation regions (6), wherein the drift sections (1) comprise a first maximum doping concentration, wherein the compensation regions (6) are in ohmic contact with the source metallization (10), wherein the semiconductor body (40) further comprises: - a second semiconductor region (2) in ohmic contact with the drift sections (1), which extends in the peripheral region (120) to the first surface (101) and which comprises a second maximum doping concentration of N-type doping materials, wherein the second maximum doping concentration is lower than the first maximum doping concentration; and - an edge termination region (7) in ohmic contact with the source metallization (10), which borders the second semiconductor region (2), which borders none of the drift sections (1) and which has a concentration of p-type dopants that varies in a vertical direction that is substantially orthogonal to the first surface (101), wherein the concentration of p-type dopants in a vertical cross-section that is substantially orthogonal to the first surface (101) is substantially mirror-symmetric with respect to a vertical axis. [13] A field effect semiconductor device according to claim 12, wherein the concentration of p-type dopant materials is highest at and / or near the first surface (101). [14] Field effect semiconductor device according to claim 12 or 13, wherein the second semiconductor region (2) and the edge termination region (7) surround the active area (110) when viewed from above, and / or wherein the edge termination region (7) extends from the first surface (101) into the second semiconductor region (2) to a depth which corresponds to at least 30% of a depth to which the compensation regions (6) extend into the semiconductor body (40). [15] Field effect semiconductor device according to one of claims 12 to 14, wherein the semiconductor body (40) comprises at least one of the following: - an edge (41) which delimits the semiconductor body (40) in a direction which is substantially parallel to the first surface (101); - at least one floating n-type semiconductor region (9) embedded in the edge termination region (7); and - an n-type channel stop region (8) comprising a third maximum doping concentration higher than the second maximum doping concentration, in ohmic contact with the second semiconductor region (2) and arranged between the edge (41) and the edge termination region (7) and / or the second semiconductor region (2). [16] A field-effect semiconductor device comprising: - a semiconductor body (40) comprising a first surface (101), an edge (41) defining the semiconductor body (40) in a direction substantially parallel to the first surface (101), an active region (110), and a peripheral region (120) disposed between the active region (110) and the edge (41); - a source metallization (10) arranged on the first surface (101); and - a drain metallization (11), wherein the semiconductor body (40) in a vertical cross-section substantially orthogonal to the first surface (101) further comprises: - a plurality of alternating first n-type column regions (1) and first p-type column regions (6) arranged in the active region (110), the first n-type column regions (1) being in ohmic contact with the drain metallization (11), the first p-type column regions (6) being in ohmic contact with the source metallization (10) and having an integral doping concentration substantially equal to an integral doping concentration of the first n-type column regions (6); - at least one second p-type column region (6') in ohmic contact with the source metallization (10), which is arranged in the peripheral region (120) and which has an integral doping concentration which is lower than the integral doping concentration of the first p-type column regions (6) divided by a number of the first p-type column regions (6); and - at least one second n-type column region (1') arranged between at least one second p-type column region (6') and the first p-type column regions (6), which extends to the first surface (101) and which has an integral doping concentration that is lower than the integral doping concentration of the first n-type column regions (1) divided by a number of the first n-type column regions (1), wherein the first n-type column regions (1), the first p-type column regions (6), and the at least one second n-type column region (1') are completely surrounded by an outer one of the at least one second p-type column regions (6') in a projection onto the first surface (101). [17] A field effect semiconductor device according to claim 16, wherein an outer one of the at least one second n-type column region (1') is arranged in the peripheral region (120) at least in vertical cross section. [18] A field effect semiconductor device according to claim 16 or 17, wherein the integral doping concentration of the at least one second p-type pillar region (6') is lower than the integral doping concentration of the at least one second n-type pillar region (1'). [19] A field effect semiconductor device according to any one of claims 16 to 18, wherein the integral doping concentration of the at least one second n-type pillar region (1') is in a range of about 50% to 99% of the integral doping concentration of the first n-type pillar regions (1) divided by the number of the first n-type pillar regions (1). [20] A field effect semiconductor device according to any one of claims 16 to 19, further comprising at least one of the following: - an edge (41) which delimits the semiconductor body (40) in a direction which is substantially parallel to the first surface (101); - a second n-type semiconductor region (2) which adjoins the at least one second p-type column region (6') in the peripheral region (120) and which comprises a second maximum doping concentration which is lower than a first maximum doping concentration of the at least one second n-type column region (1'); - a first p-type edge termination region (17) adjacent to the second semiconductor region (2); - a second n-type edge termination region (18) comprising a fourth maximum doping concentration higher than the second maximum doping concentration, adjacent to the first edge termination region (17) and arranged between the first edge termination region (17) and the first surface (101); and - an n-type channel stop region (8) comprising a third maximum doping concentration higher than the second maximum doping concentration, which is in ohmic contact with the second semiconductor region (2) and which is arranged between the edge (41) and the first edge termination region (17) and / or between the edge (41) and the second semiconductor region (2).

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