Silicon carbide semiconductor components having edge termination structures - Patents.com

Abstract

To provide a silicon carbide semiconductor component having an edge termination structure.SOLUTION: A semiconductor component (500) includes a SiC semiconductor body (100) having an active region (610) and an edge termination structure (190) surrounding the active region (610) at least partially. A first conductivity type drift zone (131) is formed in the SiC semiconductor body (100). The edge termination structure (190) includes a second conductivity type first dope region (191) between the first surface (101) of the SiC semiconductor body (100) and the drift zone (131). The first dope region (191) surrounds the active region (610) at least partially, and is placed while spaced apart from the first surface (101). The edge termination structure (190) further includes a second conductivity type second dope region (192) between the first surface (101) and the first dope region (191), and a first conductivity type third dope region (193) between the second dope regions (192).SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] This application relates to silicon carbide semiconductor components having improved edge terminations. [Background technology]

[0002] In vertical power semiconductor components, the load current flows between a first loading electrode on the front side of the semiconductor component and a second loading electrode on the rear side. In the off-state, a reverse voltage falls vertically between the first and second loading electrodes and laterally across an edge termination region between the central active area of ​​the semiconductor component and a structure formed along a lateral surface of the semiconductor body, which has the potential of the second loading electrode. With regard to the reduction of the lateral electric field, the power semiconductor component may for example include JTE (junction termination extension) regions, the dopant concentration of which may decrease with decreasing distance from the lateral or near-surface floating oppositely doped regions (so-called guard rings) that are separated from each other. In semiconductor components made of semiconductor materials with low dopant diffusion coefficients, edge termination structures as known in conventional silicon technology are less effective or are complicated to manufacture due to the abrupt pn junctions. Summary of the Invention [Means for solving the problem]

[0003] The present disclosure relates to a semiconductor component including a SiC semiconductor body having an active region and an edge termination structure at least partially surrounding the active region. A drift zone of a first conductivity type is formed within the SiC semiconductor body. The edge termination structure includes a first doped region of a second conductivity type between a first surface of the SiC semiconductor body and the drift zone. The first doped region at least partially surrounds the active region and is spaced apart from the first surface. The edge termination structure further includes a plurality of second doped regions of the second conductivity type between the first surface and the first doped region, and a third doped region of the first conductivity type between the second doped regions.

[0004] The present disclosure further relates to a semiconductor component including a SiC semiconductor body having an active region and an edge termination structure at least partially surrounding the active region, wherein a drift zone of a first conductivity type is formed within the SiC semiconductor body. The edge termination structure includes a first doped region of a second conductivity type between a first surface of the SiC semiconductor body and the drift zone. The first doped region at least partially surrounds the active region and is spaced apart from the first surface. The edge termination structure further includes a plurality of second doped regions of the second conductivity type between the first surface and the first doped region, and a third doped region between the second doped regions.

[0005] Additional features and advantages of the presently disclosed subject matter will become apparent to those skilled in the art upon reading the following detailed description and studying the drawings.

[0006] The accompanying drawings provide a further understanding of the invention, and are incorporated in and constitute a part of this disclosure. The drawings illustrate embodiments of the invention and, together with the description, explain the principles of the invention. Further embodiments of the invention, as well as intended advantages, will become apparent from a consideration of the following detailed description. [Brief description of the drawings]

[0007] [Figure 1A] 1 shows a schematic plan view of a SiC semiconductor body of a semiconductor component according to one embodiment in which a third region of opposite conductivity type is formed in a ring shape between the second doped regions, the semiconductor component including an edge termination structure having an embedded first doped region and a plurality of second doped regions spaced apart from one another between a first surface and the first doped region. [Figure 1B] 1B shows a schematic cross-sectional view of the semiconductor component of FIG. 1A along line BB. [Figure 1C] FIG. 2 shows a schematic diagram illustrating the dependence of the breakdown voltage of the semiconductor component according to FIGS. 1A and 1B as a function of the dopant amount of the edge termination structure. [Figure 1D]1 shows a schematic plan view of a SiC semiconductor body of a semiconductor component according to one embodiment, in which the second doped regions are formed in a columnar shape and are separated from each other by a third region of opposite conductivity type, and the semiconductor component includes an edge termination structure having an embedded first doped region and a plurality of second doped regions spaced apart from each other between the first surface and the first doped region. [Figure 2A] 1 shows a schematic plan view of a SiC semiconductor body of a semiconductor component according to one embodiment in which a third region (distinguishable from the second region) of the same conductivity type is formed between the second doped regions, the semiconductor component including an edge termination structure having an embedded first doped region and a plurality of second doped regions spaced apart from one another between a first surface and the first doped region. [Figure 2B] 2B shows a schematic cross-sectional view of the semiconductor component of FIG. 2A along line BB. [Diagram 3] 1 illustrates a schematic vertical cross-sectional view of a portion of a semiconductor component having an edge termination structure according to one embodiment of a semiconductor component including a transistor cell having a planar gate structure. [Figure 4] 1 shows a schematic vertical cross-sectional view of a portion of a semiconductor component having an edge termination structure according to one embodiment of a semiconductor component including a transistor cell having a shallow trench gate structure and a transistor channel on either side. [Diagram 5] 1 shows a schematic vertical cross-sectional view of a portion of a semiconductor component having an edge termination structure according to one embodiment of a semiconductor component including a deep trench gate structure and a transistor cell having a transistor channel on either side of the trench gate structure. [Figure 6] 1 shows a schematic vertical cross-sectional view of a portion of a semiconductor component having an edge termination structure according to one embodiment for a semiconductor component including a transistor cell having a deep trench gate structure and a transistor channel on one side. [Figure 7] 1 shows a schematic vertical cross-sectional view of a portion of a semiconductor component having an edge termination structure according to one embodiment for a pn diode. [Figure 8]1 shows a schematic vertical cross-sectional view of a portion of a semiconductor component having an edge termination structure according to one embodiment for a merged pin Schottky (MPS) diode. [Figure 9A] 1 illustrates a schematic vertical cross-sectional view of a portion of a semiconductor component having an edge termination structure with a shallow lateral pn junction between a second doped region and a third doped region. [Figure 9B] FIG. 9B shows a schematic diagram illustrating the lateral dopant distribution of the second and third doped regions at line BB of the edge termination structure of FIG. 9A when the conductivity types of the second and third doped regions are reversed. [Figure 9C] FIG. 9B shows a schematic diagram illustrating the lateral dopant distribution of the second and third doped regions at line BB of the edge termination structure of FIG. 9A when the second and third doped regions have the same conductivity type. [Figure 10] 1 illustrates a schematic vertical cross-sectional view of a portion of a semiconductor component having an edge termination structure including a first doped region and a second doped region between a first surface and the first doped region in accordance with a further embodiment. [Figure 11A] 11A-11C show vertical cross-sectional views of a portion of a semiconductor component having the edge termination structure of FIG. 10 with various dopant amounts in the edge termination structure in accordance with further embodiments. [Figure 11B] 11A-11C show vertical cross-sectional views of a portion of a semiconductor component having the edge termination structure of FIG. 10 with various dopant amounts in the edge termination structure in accordance with further embodiments. [Figure 11C] 11A-11C show vertical cross-sectional views of a portion of a semiconductor component having the edge termination structure of FIG. 10 with various dopant amounts in the edge termination structure in accordance with further embodiments. [Figure 11D] 11A-11C show vertical cross-sectional views of a portion of a semiconductor component having the edge termination structure of FIG. 10 with various dopant amounts in the edge termination structure in accordance with further embodiments. [Figure 11E] 11A-11C show vertical cross-sectional views of a portion of a semiconductor component having the edge termination structure of FIG. 10 with various dopant amounts in the edge termination structure in accordance with further embodiments. [Figure 11F]11A-11C show vertical cross-sectional views of a portion of a semiconductor component having the edge termination structure of FIG. 10 with various dopant amounts in the edge termination structure in accordance with further embodiments. [Figure 12A] 11B shows the distribution of avalanche events in a semiconductor component according to FIG. 11A. [Figure 12B] 11B shows the distribution of avalanche events in a semiconductor component according to FIG. [Figure 12C] 11B shows the distribution of avalanche events in a semiconductor component according to FIG. 11C. [Figure 12D] FIG. 11D shows the distribution of avalanche events in a semiconductor component. [Figure 12E] FIG. 11E shows the distribution of avalanche events in a semiconductor component. [Figure 12F] FIG. 11F shows the distribution of avalanche events in a semiconductor component. [Figure 13A] 11B shows the electric field distribution in the semiconductor component according to FIG. 11A. [Figure 13B] FIG. 11B shows the electric field distribution in the semiconductor component. [Figure 13C] FIG. 11D shows the electric field distribution in the semiconductor component. [Figure 13D] FIG. 11D shows the electric field distribution in the semiconductor component. [Figure 13E] FIG. 11E shows the electric field distribution in a semiconductor component. [Figure 13F] FIG. 11F shows the electric field distribution in the semiconductor component. [Figure 14] 1 illustrates a simplified flow diagram of a method for manufacturing a semiconductor component including an edge termination structure in accordance with a further embodiment. [Figure 15A] 1A-1C are schematic vertical cross-sectional views of a portion of a SiC semiconductor substrate illustrating a method for manufacturing a semiconductor component having an edge termination structure according to one embodiment, during a step of forming a first doped region of the edge termination structure. [Figure 15B] FIG. 15B is a schematic vertical cross-sectional view of a portion of a SiC semiconductor substrate according to FIG. 15A during a step of forming a second doped region of the edge termination structure. [Figure 16A] 1A-1C are schematic vertical cross-sectional views of a portion of a SiC semiconductor substrate illustrating a method for manufacturing a semiconductor component having an edge termination structure in accordance with a further embodiment, the views illustrating the steps of forming a first doped region of the edge termination structure; [Figure 16B] 16B is a schematic vertical cross-sectional view of a portion of a SiC semiconductor substrate according to FIG. 16A during a step of forming a second doped region of the edge termination structure; [Figure 17A] 1A-1C are schematic vertical cross-sectional views of a portion of a SiC semiconductor substrate illustrating a method for manufacturing a semiconductor component having an edge termination structure according to a next embodiment, during a step of forming a first doped region of the edge termination structure. [Figure 17B] 17B is a schematic vertical cross-sectional view of a portion of a SiC semiconductor substrate according to FIG. 17A during a step of forming a third doped region of the edge termination structure; [Figure 18] 13A-13C show schematic cross-sectional views of a portion of a SiC semiconductor substrate illustrating a method of forming a second doped region of an edge termination structure having a shallow lateral pn dopant concentration junction according to a further embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] In the following detailed description, reference is made to the accompanying drawings, which form a part of this disclosure and show, for the purpose of illustration, certain exemplary embodiments. It will be appreciated that further exemplary embodiments exist, and structural or logical changes to the exemplary embodiments may be made without departing from what is defined by the claims. In this respect, the description of the exemplary embodiments is non-limiting. In particular, elements of an exemplary embodiment described below may be combined with elements of another exemplary embodiment described below, unless the context clearly indicates otherwise.

[0009] In the following, the words "have", "contain", "encompass", "comprise" and the like are open terms indicating the presence of stated elements or features and not excluding the presence of other elements or features. The indefinite and definite articles include both the plural and the singular, unless the context clearly dictates otherwise.

[0010] In some figures, relative dopant concentrations are represented by displaying a "-" or "+" next to the doping type. For example, an "n-" represents a dopant concentration that is lower than that of an "n" doped region, and an "n+" doped region has a higher dopant concentration than an "n" doped region. The display of relative dopant concentrations does not necessarily imply that doped regions that are displayed with the same relative dopant concentration have the same absolute dopant concentration, unless otherwise specified. For example, two different "n" doped regions may have the same or different absolute dopant concentrations.

[0011] The phrase "electrically connected" refers to a low impedance connection between the electrically connected elements, e.g., a direct connection between the elements or a connection via a metal and / or a highly doped semiconductor. The expression "electrically coupled" encompasses the fact that there may be one or more intervening elements suitable for signal transmission between the "electrically coupled" elements, such as controllable elements capable of creating a low impedance connection in a first state and a high impedance decoupling in a second state.

[0012] 1A-1C show a semiconductor component 500, which includes a central active area 610 and includes edge termination regions 690 surrounding the active area 610 on all sides. Element structures 601, which determine the functionality of the semiconductor component 500, are formed in the active area 610. The element structures 601 may include, for example, various transistor cells TC, pn junctions of pn diodes, or MPS structures. The semiconductor component 500 may be a pn diode, an MPS diode, an IGBT (insulated gate bipolar transistor), or an IGFET (insulated gate field effect transistor), for example a MOSFET (metal oxide semiconductor FET), where the abbreviation MOSFET encompasses not only FETs with a metal gate electrode, but also FETs with a gate electrode made of a semiconductor material. The semiconductor component 500 may be an MGD (MOS gated diode) or a semiconductor component which includes further electronic elements in addition to the transistor cells TC.

[0013] The semiconductor component 500 may be based on a SiC semiconductor body 100 made of monocrystalline silicon carbide (SiC), for example 2H SiC (2H polytype of SiC), 6H SiC or 15R SiC. According to an embodiment, the material of the SiC semiconductor body 100 is 4H SiC. The front first surface 101 of the SiC semiconductor body 100 is flat or ribbed. A perpendicular 104 to the mid-plane of the flat or ribbed first surface 101 or the ribbed first surface 101 defines the vertical direction. The direction parallel to the mid-plane of the flat or ribbed first surface 101 or the ribbed first surface 101 is the horizontal or lateral direction.

[0014] On the rear side, the SiC semiconductor body 100 has a second surface 102 parallel to the first surface 101. The total thickness of the SiC semiconductor body 100 between the first surface 101 and the second surface 102 may range from a few hundred nanometers to a few hundred micrometers. Side surfaces 103 form the lateral outer surfaces of the SiC semiconductor body 100 and connect the first surface 101 and the second surface 102. The side surfaces 103 may be oriented perpendicular to the first surface 101.

[0015] A drift structure 130 is formed in the SiC semiconductor body 100, the drift structure including at least one highly doped contact segment 139 along the second surface 102, and a lightly doped drift zone 131 of a first conductivity type between the first surface 101 and the highly doped contact segment 139. In addition to the drift zone 131 and the contact segment 139, the drift structure 130 may include further doped regions of the conductivity type of the drift zone 131, or of the opposite conductivity type.

[0016] Edge termination region 690 is adjacent to side 103 of SiC semiconductor body 100 and does not include any semiconductor elements (e.g., transistor cells) that determine the functionality of the semiconductor component. Instead, edge termination structure 190 for reducing the lateral electric field is formed in edge termination region 690. Edge termination region 690 may include, in addition to edge termination structure 190 for reducing the lateral electric field, further edge structures having doped regions, for example, a channel stop region of a conductivity type of drift zone 131 that is more highly doped than drift zone 131, and may extend from first surface 101 into SiC semiconductor body 100 between edge termination structure 190 and side 103.

[0017] The edge termination structure 190 includes a first doped region 191 of a second conductivity type, which is complementary to the first conductivity type of the drift zone 131. The first doped region 191 is formed together with the drift structure 130, e.g., the drift zone 131, between the first surface 101 and the drift zone 131 to form a pn junction that extends mostly or entirely parallel to the first surface 101. The vertical extent of the first doped region 191 may be in the range of 500 nm to 2.5 μm, e.g., in the range of 0.8 μm to 1.2 μm. The distance between the first doped region 191 and the first surface 101 may be in the range of 100 nm to 1 μm. In a lateral direction parallel to the outer edge of the active area 610, the dopant concentration is approximately constant, at least in straight sections. In a lateral direction perpendicular to the outer edge of the active area 610, the dopant concentration of the second doped region 192 may be approximately constant over a wide area, for example, approximately constant over at least 90% of the lateral width w1 of the second doped region 192.

[0018] The first doped region 191 is capable of completely depleting mobile charge carriers under the range of operating and ambient conditions specified in the data sheet for the semiconductor component 500 in the maximum limit data for off-state operation. For example, the dopant amount of the first doped region 191 is 2×10 12 cm -2 From 2 × 10 13 cm -2 For example, the range is 6×10 12 cm -2 From 10 13 cm -2 The range is.

[0019] The edge termination structure 190 further includes second doped regions 192 that are laterally spaced apart from one another and in each case at least partially surround the active area 610. According to one embodiment, at least one of the second doped regions 192 forms a closed structure that completely surrounds the active area 610. Other second doped regions 192 may be formed along lines that laterally frame the active area 610, and these second doped regions 192 are spaced apart from one another along those lines. According to the embodiment of FIG. 1A, all second doped regions 192 form a closed structure that completely surrounds the active area 610 in each case.

[0020] The second doped region 192 is formed between the first surface 101 and the first doped region 191, and may be adjacent to the first surface 101, the first doped region 191, or both. According to one embodiment, the second doped region 192 extends from the first surface 101 to the first doped region 191. The dopant amount of the second doped region 192 is higher than the dopant amount of the first doped region 191, e.g., at least four times higher. According to one embodiment, the dopant concentration of the second doped region 192 is at least 1×10 17 cm -3 It is.

[0021] The total dopant amount in edge termination structure 190, including first doped region 191 and second doped region 192, is about 2×10 13 cm -2 From 6×10 13 cm -2 For example, the range is 3×10 15 cm -2 From 5×10 13 cm -2 The range may be:

[0022] Third doped regions 193 of the first conductivity type laterally separate adjacent second doped regions 192 from each other.

[0023] The first doped region 191 and the innermost second doped region 192 facing the active area 610 may be immediately adjacent to doped regions of the same conductivity type formed in the active area 610. The vertical extent of the edge termination structure 190 may be at least 80% of the distance between the first surface 101 and the bottom end of the deepest doped region of the second conductivity type in the active area 610.

[0024] In the off state, the second doped region 192 contributes to reducing the lateral electric field. The relatively lightly doped first doped region 191 shields the also relatively abrupt lateral pn junction in the silicon carbide between the second doped region 192 and the third doped region 193 to the bottom, thus reducing the maximum electric field strength occurring at the lateral pn junction in the edge termination structure 190. The buried first doped region 191 thus allows, among other things, a high dopant content in the second doped region 192, which reduces the effect of charge carriers that may occupy surface states along the interface between the SiC semiconductor body 100 and the passivation structure resting on the first surface 101. The dielectric strength of the edge termination structure 190 therefore remains constant over extended periods of operation and regardless of the operating environment.

[0025] In this case, the passivation structure may consist of a layer of dielectric material or may include multiple layers of different dielectric materials, such as, for example, silicon oxide produced by oxidation of silicon carbide, deposited silicon oxide, nitrogenous silicon oxide, glass (e.g., USG (undoped silicate glass), BSG (borosilicate glass), PSG (phosphosilicate glass), or BPSG (borophosphosilicate glass)), or polyimide.

[0026] Compared to an edge termination structure that only includes a lightly doped ring structure of the second conductivity type, fabricated using only one lithography mask plane, edge termination structure 190 is significantly less sensitive to lithography variations, i.e., variations in the distance between second doped regions 192. Furthermore, due to the shielding effect of first doped regions 191, the electric field strength at the lateral p-n junction is significantly lower, which has a beneficial effect on the stability and reliability of the semiconductor component and improves the scalability of the semiconductor component to higher voltage classes.

[0027] Compared to edge termination structures based on multi-zone implantation with continuous, near-surface edge termination regions of a second conductivity type, in which the dopant concentration in the zones decreases as the distance between the zones increases, edge termination structure 190 can be fabricated with fewer mask planes, for example, if the fabrication of first and second doped regions 191, 192 can be linked with the formation of doped regions of the same conductivity type in active area 610.

[0028] FIG. 1C illustrates the dependence of breakdown voltage VBD of edge termination structure 190 on dopant dose Dos for a first doped region 191 of a semiconductor component including edge termination region 610, defined for a reverse voltage of 650V.

[0029] Line 401 represents the dependence of the breakdown voltage VBD on the dopant dose Dos of the first doped region. Line 402 represents the breakdown voltage in the active region 610. The horizontal axis is scaled with a constant reference amount of 4×10 12 cm -2 The dopant concentration in the first doped region 191 is expressed as a percentage of the dopant concentration in the first doped region 191 relative to the dopant concentration in the first doped region 191 .

[0030] This figure illustrates that edge termination structure 190 allows for a very wide process window for the dopant dosage of second doped region 192, such that the breakdown voltage of edge termination structure 190 is nearly independent of process variations for edge termination structure 190. Thus, avalanche breakdown in semiconductor component 500 is securely bound to active region 610, thereby significantly improving the stability and avalanche robustness of semiconductor component 500. And in active region 610, avalanche breakdown may be pinned, for example, to the curvature of a doped region of second conductivity type formed therein.

[0031] 1D shows the second doped regions 192 formed in a columnar shape and along a straight border that frames the active area 610. The second doped regions 192 on the same border are separated from each other by another third doped region 193.

[0032] 2A and 2B , the third doped region 193 of the edge termination structure 190 is of the same conductivity type as the second doped region 192 and the first doped region 191, and the dopant amount of the second doped region 192 is greater than the dopant amount of the third doped region 193. According to one embodiment, the dopant amount of the second doped region 192 is at least four times the dopant amount of the first doped region 191. According to another embodiment, the dopant concentration of the third doped region 193 may approximately match the dopant concentration of the first doped region 191, i.e., may deviate from the dopant concentration of the first doped region 191 by at most 10% of its dopant concentration value.

[0033] Compared to a JTE structure that includes alternating highly doped and lightly doped rings, in which the width of the highly doped rings decreases and the width of the lightly doped rings increases to a similar extent as they move away from the active region 610, the edge termination structure 190 according to FIGS. 2A-2B has been found to be more robust to lithography variations, for example for relatively low voltage classes (e.g., 650V or 1200V).

[0034] 3 shows a semiconductor component 500 including a SiC semiconductor body 100 with an edge termination region 690 surrounding a central active area 610 with transistor cells TC. On the front side of the SiC semiconductor body 100, planar gate structures 150 of the transistor cells TC are formed, which gate structures 150 are assigned, at least within the active area 610, in each case to two transistor cells TC that are formed symmetrically with respect to the respective gate structures 150.

[0035] The gate structure 150 comprises a conductive gate electrode 155 and a gate dielectric 151, which is formed directly on the first surface 101 and separates the gate electrode 155 from the SiC semiconductor body 100. The body regions 120 extending from the first surface 101 into the SiC semiconductor body 100 are in each case assigned to two adjacent transistor cells TC, which are in part assigned to the two adjacent gate structures 150. The source regions 110 of the two adjacent transistor cells TC are formed between the first surface 101 and the body region 120. The body region 120 may include a contact region 149, in which the dopant concentration is higher than in a main region 121 of the body region 120 outside the contact region 149. The contact region 149 adjoins the first surface 101 between the two source regions 110.

[0036] A drift structure 130 having a drift zone 131 and a contact section 139 separates the transistor cell TC from the second surface 102 of the SiC semiconductor body 100, and the drift structure 130, e.g., the drift zone 131 or a current spreading zone having the same conductivity type as the drift zone 131 but a higher dopant concentration than the drift zone 131, may extend between adjacent body regions 120 and under the gate electrode 155 to the first surface 101.

[0037] In the switched-on state, the transistor cell TC forms a lateral inversion channel in a channel region of the body region 120 along the gate dielectric 151, which inversion channel connects the source region 110 to a section of the drift structure 130 adjacent to the first surface 101, such as the drift zone 131 or current spreading zone.

[0038] An interlayer dielectric 210 separates the gate electrode 155 from a first charging electrode 310 on the front side of the SiC semiconductor body 100. A contact structure 315 extending through an opening in the interlayer dielectric 210 electrically connects the first charging electrode 310 to the contact region 149 and the source region 110. A second charging electrode 320 may be adjacent the highly doped contact section 139 of the drift structure 130. The gate electrode 155 is electrically connected or coupled to a gate terminal of the semiconductor component.

[0039] In the illustrated exemplary embodiment, the semiconductor component 500 is an n-channel SiC MOSFET. The first conductivity type is n-type and the second conductivity type is p-type. The first charging electrode 310 may form or be electrically connected to a source terminal S. The second charging electrode 320 may form or be electrically connected to a drain terminal D. According to another embodiment, the first conductivity type is p-type and the second conductivity type is n-type.

[0040] In the edge termination region 690, the edge termination structure 190 described above is formed. The first doped region 191 may extend below the outermost gate structure 150 or may be laterally spaced from the gate structure 150. The lateral width of the second doped region 192 may decrease with distance from the active region 610. Additionally or alternatively, the lateral width of the third doped region 193 may increase with distance from the active region 610.

[0041] A dielectric passivation structure, e.g., polyimide structure 400, may be directly on at least one section of first surface 101 of edge termination region 690 and may cover an outer edge of first loading electrode 310 or outermost gate structure 150. According to another embodiment, in at least one inner partial region of edge termination region 690 adjacent active area 610, interlayer dielectric 210 may separate polyimide structure 400 from SiC semiconductor body 100. At least one further dielectric layer, e.g., a silicon oxide layer and / or a layer of silicate glass, may be formed at least in the section between polyimide structure 400 and SiC semiconductor body 100.

[0042] Surface states at the interface between the SiC semiconductor body 100 and the passivation structure (e.g., polyimide structure 400), as well as the interface between the SiC semiconductor body 100 and the interlayer dielectric 210, may be occupied to various degrees by charge carriers during operation of the semiconductor component 500, which may affect the electric field distribution in the edge termination region 610, as well as the breakdown voltage of the edge termination structure 190. According to one embodiment, the dopant concentration of the second doped region 192 is at least 1×10 17 cm -3 , e.g., at least 2 x 10 17 cm -3 , whereby charge carriers that at least temporarily occupy surface states at the boundary layer between polyimide structure 400 and SiC semiconductor body 100 have negligible effect on the dielectric strength of edge termination region 690.

[0043] According to one embodiment, the dopant amount of the second doped region 192 is approximately equal to the dopant amount of the contact region 149 or approximately equal to the difference between the dopant concentration of the contact region 149 and the dopant concentration of the body region 120, thereby allowing the second doped region 192 and the contact region 149 to be defined in the same mask plane in the same implantation step.

[0044] The doping of first doped region 191 is selected such that it is possible to completely deplete first doped region 191 during operation of semiconductor component 500. Because the doping of body region 120 is selected such that body region 120 is not depleted, the formation of body region 120 typically includes at least one method step unrelated to the formation of first doped region 191.

[0045] The vertical extent v1 of the first doped region 191 of the edge termination region 690 may correspond to the distance v3 between the lower end of the body region 120 and the first surface 101, or may be at least 80%, for example at least 85%, of the distance v3, which in this exemplary embodiment corresponds to the vertical extent of the body region 120 including the contact region 149, thereby preventing localized degradation of the blocking capability at the junction between the body region 120 and the edge termination structure 190.

[0046] The semiconductor component 500 of FIG. 4 is a SiC TMOSFET (SiC trench MOSFET) that includes a gate structure 150 formed in a shallow trench having a generally v-shaped vertical cross-sectional area. The gate structure 155 may extend with a generally uniform thickness along the sidewalls and bottom of the gate structure 150. A mesa portion 180 between adjacent gate structures 150 of the SiC semiconductor body 100 includes a source region 110 formed along the first surface 101 and a body region 120 that separates the source region 110 from the drift structure 130. The body region 120 may include a highly doped contact region 149 having a higher dopant concentration than a main region 121 of the body region 120 outside the contact region 149. The sidewalls of the mesa portion 180 may be, for example, a (0-33-8) lattice plane.

[0047] The SiC TMOSFET includes, as described above, a drift structure 130 and an edge termination structure 190. The vertical extent v1 of the edge termination structure 190 may be at least 80% of the distance v3 between the bottom end of the body region 120 and the first surface 101, or may be, for example, approximately equal to the distance v3, which in the exemplary embodiment of FIG.

[0048] 5 is a SiC TMOSFET that includes a gate structure 150 extending into the SiC semiconductor body 100 from the first surface 101, with sidewalls of the gate structure 150 extending vertically to the first surface 101. A body region 120 is formed in a mesa portion 180 of the SiC semiconductor body 100 between adjacent gate structures 150, the body region forming a first pn junction pn1 with the drift structure 130 in the mesa portion 180, and a second pn junction pn2 with a source region 110 formed along the first surface 101. The side of the mesa portion 180 is a main lattice plane of the silicon carbide crystal.

[0049] Between adjacent gate structures 150, a trench contact 316 extends from the first loading electrode 310, through the interlayer dielectric 210, and into the mesa portion 180. The trench contact 316 is laterally adjacent to the source region 110 and connects the source region 110 to the first loading electrode 310.

[0050] The transistor cell TC further includes a shield region 160 of the conductivity type of the body region 120, with a distance v4 between the lower end of the shield region 160 and the first surface 101 being greater than the vertical distance v2 of the gate structure 150. The shield region 160 may have a higher dopant concentration than the body region 120 and is laterally spaced apart from the gate structure 150. The gate structure 150 is shielded against the drain potential by two adjacent shield regions 160 in each case, the shield region 160 being much closer to the second surface 102 than the gate structure 150. In the active region 610, it is possible to pin the avalanche breakdown in a region of the shield region 160, for example along the lower end of the shield region 160. The shield region 160 may include a highly doped contact region 149 formed directly under the trench contact 316.

[0051] Edge termination region 690 of semiconductor component 500 includes edge termination structure 190, as described above. In this case, edge termination structure 190 may have a vertical extent v1 that corresponds approximately to distance v4 between the lower end of shield region 160 and first surface 101, e.g., at least 80% of distance v4. If contact region 149 is introduced through the bottom of the contact trench prior to formation of trench contact 316, second doped region 192 may be formed from the same implantation and in the same mask plane as heavily doped contact region 149, and the absolute dopant concentration of the second conductivity type in second doped region 192 may correspond approximately to the difference between the dopant concentration of contact region 149 and the dopant concentration of shield region 160.

[0052] 6, the semiconductor component 500 is an n-channel SiC TMOSFET based on a SiC semiconductor body 100 having a strip-shaped transistor cell TC and a deep trench gate structure 150 with a transistor channel on one side. For details of the edge termination structure 190 not described below, see the description of FIGS. 1A and 1B.

[0053] The SiC semiconductor body 100 has a first surface 101 on the front side, which may include surface portions that are in the same plane. The first surface 101 may coincide with a main lattice plane or may extend obliquely with respect to the main lattice plane, for example with an angle deviation α with respect to the (0001) lattice plane, which may be at most 12°, for example approximately 4°.

[0054] In the illustrated embodiment, <0001> The crystal directions are inclined by an angle deviation α with respect to the normal 104. The <11-20> crystal directions are inclined by the same angle deviation α with respect to the horizontal plane and otherwise extend in the plane of the cross section. The <1-100> crystal directions are perpendicular to the plane of the cross section.

[0055] On the rear side, the SiC semiconductor body 100 has a second surface 102 parallel to the first surface 101. The total thickness of the SiC semiconductor body 100 between the first surface 101 and the second surface 102 may be from a few hundred nanometers to a few hundred micrometers.

[0056] A drift structure 130 formed in a SiC semiconductor body 100 includes at least one highly doped contact segment 139 adjacent to the second surface 102 and includes a lightly doped drift zone 131 of a first conductivity type between the first surface 101 and the highly doped contact segment 139.

[0057] The highly doped contact section 139 is of the same conductivity type as the drift zone 131 and may be or include a substrate section sawn or sliced ​​from the crystal, or may be entirely epitaxied. The contact section 139 forms an ohmic contact with the second charging electrode 320, which may be directly adjacent to the second surface 102. Along the second surface 102, the dopant concentration of the contact section 139 is high enough to form a low impedance contact with the second charging electrode 320.

[0058] The drift zone 131 may be formed in a layer grown by epitaxy on the contact section 139. The drift zone 131 may have an average dopant concentration of, for example, 5×10 14 cm -3 From 5×10 16 cm -3 In addition to the drift zone 131 and the contact sections 139, the drift structure 130 may include further doped regions, such as field stop zones, blocking or barrier zones, and / or current spreading zones of the conductivity type of the drift zone 131, and / or island regions of a complementary conductivity type.

[0059] The transistor cells TC on the front side of the SiC semiconductor body 100 are formed along with gate structures 150 that extend into the SiC semiconductor body 100 from the first surface 101 , with mesa portions 180 of the SiC semiconductor body 100 separating adjacent gate structures 150 .

[0060] The longitudinal extent of the gate structure 150 along a first horizontal direction is greater than the width of the gate structure 150 across said longitudinal extent along a second horizontal direction perpendicular to the first horizontal direction. The gate structure 150 may be a long trench extending from one side to the other of the active area 610 containing the transistor cells TC, and the length of the gate structure 150 may be up to several hundred micrometers or up to several millimeters.

[0061] According to another embodiment, the gate structures 150 may be formed along parallel lines extending in each case from one side of the cell array region to the other, and in each case a number of spaced apart gate structures 150 are formed along the same lines. The gate structures 150 may form a lattice with mesa portions 180 within the mesh of the lattice.

[0062] The gate structures 150 may be spaced apart from one another, may have the same width, may form a regular pattern, and the center-to-center distance between the gate structures 150 may range from 1 μm to 10 μm, such as from 2 μm to 5 μm. The vertical extent of the gate structures 150 may range from 300 nm to 5 μm, such as from 500 nm to 2 μm.

[0063] The sidewalls of the gate structure 150 are slightly inclined with respect to the vertical, and the opposing sidewalls may run parallel to each other or may run towards each other. According to one embodiment, the width of the gate structure 150 decreases with distance from the first surface 101. For example, one sidewall deviates from the vertical by an angle deviation α and the other sidewall deviates from the vertical by −α.

[0064] The mesa portion 180 has two opposing longitudinal mesa sides 181, 182 that are directly adjacent to two adjacent gate structures 150. The first mesa side 181 lies in a (11-20) lattice plane with high charge carrier mobility. The second mesa side 182 opposite the first mesa side 181 may be inclined with respect to the lattice plane by times the angle deviation α, for example about 8 degrees.

[0065] The gate structure 150 includes a conductive gate electrode 155, which may include a highly doped polycrystalline silicon layer, an integral or segmented metal structure, or both. The gate electrode 155 is electrically connected to a gate metallization on the front side of the component, which forms a gate terminal or is electrically connected or coupled to such a terminal.

[0066] Along at least one side of the gate structure 150, a gate dielectric 151 separates the gate electrode 155 from the SiC semiconductor body 100. The gate dielectric 151 may comprise a semiconductor dielectric (e.g., a thermally grown or deposited semiconductor oxide (e.g., silicon oxide)), a semiconductor nitride (e.g., a deposited or thermally grown silicon nitride), a semiconductor oxynitride, e.g., silicon oxynitride, some other deposited dielectric material, or any combination of these materials. The layer thickness of the gate dielectric 151 may be a few tens of nanometers and may be selected such that the threshold voltage of the transistor cell TC is in the range of 1 V to 8 V.

[0067] The gate structure 150 may include only the gate electrode 155 and the gate dielectric 151, or may include other conductive and / or dielectric structures (eg, insulating dielectrics) in addition to the gate electrode 155 and the gate dielectric 151.

[0068] In the mesa portions 180, source regions 110 are formed towards the front side of the SiC semiconductor body 100, and the source regions may be directly adjacent to the first surface 101 and the first mesa side surface 181 of each mesa portion 180. In this case, the source region 110 may be included in each mesa portion 180 having multiple portions connected to each other in the SiC semiconductor body 100, or having at least two portions that are separate from each other in the SiC semiconductor body 100 and connected to each other with low impedance by contacts or trench contacts adjacent to the mesa portion 180.

[0069] The mesa portion 180 further includes a body region 120 separating the source region 110 from the drift structure 130 and adjacent to a first mesa side 181. The body region 120 forms a first pn junction pn1 with the drift structure 130 and a second pn junction pn2 with the source region 110. In a switched-on state of the transistor cell TC, an inversion channel is formed in the body region 120 along the gate structure 150 connecting the source region 110 and the drift structure 130. The extent of the body region 120 along the first mesa side 181 corresponds to the channel length of the transistor cell TC and may be between 200 nm and 1500 nm.

[0070] The mesa portion 180 further includes at least a portion of a shield region 160 of the conductivity type of the body region 120, the shield region 160 adjacent the second mesa side 182 and forming an ohmic contact with the first loading electrode 310. The shield region 160, or at least the portion of the shield region 160, may be more highly doped than the body region 120. For example, a dopant concentration p2 of the shield region 160 along the second mesa side 182 may be at least five times higher than a dopant concentration p1 of the body region 120 along the first mesa side 181.

[0071] The shield region 160 may be formed between the body region 120 and the second mesa side 182 and directly adjacent to the body region 120. The vertical extent of the shield region 160 may be greater than the vertical extent of the body region 120, e.g., greater than the vertical extent of the gate structure 150. A highly doped contact region 149 may be formed in the shield region 160, which may connect the contact structure 315 to the first loading electrode 310. A partial region of the shield region 160 may be formed directly between the bottom of the gate structure 150 and the second surface 102 and may shield the gate structure 150 against the potential of the second loading electrode 320.

[0072] A load current flowing through the SiC semiconductor body 100 between the first and second loading electrodes 310, 320 in the switched-on state of the semiconductor component 500 passes through the body region 120 as minority charge carriers flow through an inversion channel induced along the gate dielectric 151. The dopant concentration of the shield region 160 is higher than the dopant concentration of the body region 120, which suppresses the formation of an inversion channel along the second mesa side 182 when operating at the maximum limit data.

[0073] FIG. 6 further shows a current spreading zone 137 that is part of the drift structure 130, which forms a first pn junction pn1 with the body region 120 and is directly adjacent to the drift zone 131, and the dopant concentration of the current spreading zone 137 is higher than the dopant concentration of the drift zone 131, for example at least twice the dopant concentration of the drift zone 131.

[0074] The vertical extent v1 of edge termination region 190 may be at least 80% of the vertical extent v4 of shield region 160 including contact region 149, such as at least 85%, or may be the same size.

[0075] 7 is a pn diode having an active area 610 in which a p-doped anode region 125 may be formed as a continuous layer. An edge termination structure 190 may be immediately adjacent laterally to the anode region 125. The vertical extent v1 of the edge termination structure 190 is at least 80% of the vertical extent v7 of the anode region 125. According to one embodiment, the vertical extent v1 of the edge termination structure 190 is equal to the vertical extent v7 of the anode region 125, which may prevent a localized reduction in blocking capability at the junction of the edge termination structure 190 and the anode region 125.

[0076] The semiconductor component 500 of FIG. 8 is an MPS diode, in whose active region 610 the channel portion 136 of the drift structure 130 extends to the first surface 101 to form a Schottky contact SC to the first load electrode 310. The dopant concentration of the channel portion 136 may be equal to or greater than the dopant concentration of the drift zone 131. The anode region 125 of the second conductivity type, which extends from the first surface 101 into the SiC semiconductor body 100, is also adjacent to the first load electrode 310. In the low load range, the MPS diode uses a lower forward voltage of the Schottky contact SC, and the bipolar current through the pn junction may contribute increasingly more to higher load currents. In the off state, a space charge zone extending laterally from the anode region 125 into the channel portion 136 pinches off the leakage current path through the channel portion 136.

[0077] 9A-9B show the lateral dopant distribution of the second and third doped regions 192, 193 of the edge termination structure 190 described in the previous figures, where the dopant concentration of the first conductivity type dopant in the third doped region 193 matches the dopant concentration ND0 of the same dopant in the drift zone 131.

[0078] The second doped region 192 and the third doped region 193 have a constant background doping 761 of the conductivity type of the drift zone 131 due to the dopant concentration ND0 of the drift zone 131. At least in the edge portion of the second doped region 192, the concentration 762 of the dopant of the conductivity type opposite to that of the drift zone 131 decreases continuously, so that along the same direction, the net dopant concentration 763 decreases from a maximum value Nmax to a value Nmax / e (e represents Euler's number) within a lateral distance Δx of at least 200 nm (for example at least 500 nm). The decrease to 1 / e corresponds approximately to a decrease from 100% to 37%. In the central portion of the second doped region 192, the net dopant concentration 763 may be approximately constant.

[0079] FIG. 9C represents the lateral distribution of the net dopant concentration 763 along line BB when the third doped region 193 is fully counter doped.

[0080] The lateral dopant distributions shown in Figures 9A-9C result when the ion beam used to form the second doped region 192 by ion implantation is so laterally modulated. For example, the ion beam may be laterally modulated using an energy filter placed in the beam path of the ion beam, or using a suitable neutral graded mask, for example, formed by temporarily heating the graded mask, the material of which sags a little as a result of the heating. Lateral modulation of the ion beam also results when the ion beam is directed at various angles through an opening of sufficient height in a graded mask.

[0081] 10 illustrates a longitudinal cross section through an edge termination region 690 between an active region 610 and a side surface 103 of a SiC semiconductor body 100 of a semiconductor component 500. A first doped region 191 and an innermost second doped region 192 of an edge termination structure 190 are immediately adjacent to a doped region of the same conductivity type in the active region 610, e.g., a body region, or an anode region 125. The dopant amount of the second doped region 192 is, for example, four times the dopant amount of the first doped region 191.

[0082] The second doped region 192 is introduced by one or more (e.g., three) implantations of varying energies through openings in an implantation mask. In either case, the width ws of the substructure 195 formed from the second doped region 192 and the third doped region 193 adjacent to the second doped region 192 on a side facing away from the active region 610 remains constant, the lateral width w2 of the second doped region 192 decreases as it moves away from the active region 610, and the lateral width w3 of the third doped region 193 correspondingly increases as it moves away from the active region 610. The decrease in lateral width w2, as well as the increase in lateral width w3, may be provided linearly, i.e., in uniform steps.

[0083] 11A-13F below show the dopant distribution, avalanche rate, and electric field distribution for the structure according to FIG. 10, where the dopant amount in edge termination structure 190 is varied in each case.

[0084] Reference dopant amount 1×10 13 cm -2 Whereas, Figures 11A, 12A, and 13A relate to a dopant amount of 40%, Figures 11B, 12B, and 13B relate to a dopant amount of 120%, Figures 11C, 12C, and 13C relate to a dopant amount of 200%, Figures 11D, 12D, and 13D relate to a dopant amount of 400%, Figures 11E, 12E, and 13E relate to a dopant amount of 680%, and finally Figures 11F, 12F, and 13F relate to a dopant amount of 800%.

[0085] 11A-11F, the line 403 represents in each case the boundary of the space charge zone at the moment of avalanche breakdown. For implantation doses of 120% and above, the breakdown point is pinned independent of the implantation dose in the active area 610.

[0086] 12A-12F show the distribution of the impact ionization density K in each case, and show that the location of the maximum impact ionization density remains unchanged for implantation doses from 120% to 800%.

[0087] 13A-13F show the distribution of electric field strength E in each case, showing a homogeneous potential distribution that increases with implantation dose from the inner region outward over a wide range of implant doses, from 120% to 800%.

[0088] According to FIG. 14, a method for manufacturing a component includes a step (902) of forming a counter-doped zone in an initial layer of a SiC semiconductor substrate, the initial layer being of a first conductivity type, the counter-doped zone partially or completely surrounding an active area of ​​the component region. The method further includes a step (904) of forming a second doped region of a second conductivity type, the second doped region extending from a first main surface of the SiC semiconductor substrate to the first doped region, being laterally spaced apart from one another and in each case at least partially or completely surrounding the active area. The first doped region is formed from at least one portion of the counter-doped zone. The first doped region, the second doped region and a third doped region between the second doped regions form an edge termination structure.

[0089] The second doped region may be formed with a dopant amount greater than the first doped region. The counterdoped zone may be formed at a distance from the first main surface, the second doped region extending from the first main surface to the counterdoped zone, the first doped region being formed by the counterdoped zone. Alternatively to this, the counterdoped zone may be formed extending from the first main surface, the second doped region having a vertical extent smaller than the vertical extent of the counterdoped zone, the first doped region being formed by a portion of the counterdoped zone vertically adjacent to the second doped region. The step of forming the second doped region may include the step of introducing a dopant of the second conductivity type into sub-regions of the initial layer that are laterally spaced apart from one another. The step of forming the second doped region may include forming a second doped zone of the second conductivity type extending from the first main surface into the initial layer, and at least partially counterdoping a portion of the second doped zone with a dopant of the first conductivity type. The step of forming the second or third doped region may include ion implantation with a laterally modulated ion beam, whereby in the second or third doped region, the lateral net dopant distribution continuously decreases from a maximum net dopant concentration Nmax to a concentration Nmax / e (where e is Euler) within at least 200 nm (e.g., at least 500 nm).

[0090] 15A and 15B relate to a method in which a first doped region 191 is formed independently of a second doped region 192. FIG.

[0091] A SiC semiconductor substrate 700 is provided that includes a highly doped substrate portion 790 and an initial layer 730 grown (eg, by epitaxy) on substrate portion 790.

[0092] In the illustrated exemplary embodiment, both the substrate portion 790 and the initial layer 730 are n-doped. The initial layer 730 may be uniformly doped, with an average dopant concentration of 5×10 14 cm -3 From 5×1016 cm -3 At a distance from the first main surface 701, a counter-doped zone 791 is formed.

[0093] 15A shows the formation of counterdoped zones 791 by implanting a first dopant 481 through openings 485 in a first implantation mask 480. The implantation to form counterdoped zones 791 may include a single implantation or multiple implantations at various implantation energies. An energy filter may be placed in the beam path of the ion beam to spread the implant vertically.

[0094] The distance between the counterdoped layer 791 and the first main surface 701 may be several hundreds of nanometers, for example at least 500 nm and at most 2 μm. At least one partial layer 725 of the shielding region of the body region or the anode region may be formed through a further mask opening 485 in the active area 610 of the component region.

[0095] Fig. 15B shows how the second doped region 192 is formed by ion implantation of a second dopant 491 through an opening 495 in a second implantation mask 490. Instead of the second implantation mask 490, a correspondingly structured energy filter may be placed in the beam path of the ion beam. The second doped region 192 may be formed to extend from the first main surface 701 to the counterdoped zone 791 of Fig. 15A.

[0096] The counter-doped zones 791 form the first doped regions 191 of the edge termination structure 190. The initial doping of the initial layer 730 is maintained in the areas between the second doped regions 192 that are covered by the masked portions of the second implantation mask 490. This area forms the third doped region 193 of the edge termination structure 190. For example, through further openings 495 in the second implantation mask 490 in the active area 610, a contact region of the body region, a contact region of the shield region, or a contact region 149 of the anode region 125 may be formed.

[0097] According to the embodiment shown in FIGS. 16A-16B, a counter-doped zone 791 created using the first implantation mask 480 extends from the first main surface 701 into the initial layer 730.

[0098] 16A shows that a counter-doped zone 791 is formed, which may include multiple implantations at various implantation energies. Simultaneously with the counter-doped zone 791, a body region, a shield region, or an anode region 125 adjacent the first main surface 701 may be formed through further mask openings in the active area 610.

[0099] FIG. 16B illustrates the formation of second doped region 192, which may be defined, for example, using second implantation mask 490 as shown in FIG. 15B. The initial doping of counterdoped zone 791 is maintained in the area of ​​counterdoped zone 791 covered by second implantation mask 490. This area forms third doped region 193 of edge termination structure 190, where third doped region 193 has the same conductivity type as second doped region 192 and is distinguishable from second doped region 192 only by a lower dopant concentration. For example, third doped region 193 has a dopant concentration that is only 25% of the dopant concentration of second doped region 192. For example, third doped region 193 has the same dopant concentration as first doped region 191.

[0100] FIG. 17A illustrates the formation of a counterdoped zone 791 extending from the first main surface 701 into the SiC semiconductor substrate 700, with an upper portion of the counterdoped zone 791 between the first main surface 701 and a lower portion of the counterdoped zone 791 being formed with a higher dopant concentration than the lower portion.

[0101] 17B shows a third implantation mask 470 with a mask opening 475 exposing the area in which the third doped region 193 is formed, and in the area covered by the third implantation mask 470, the second doped region 192 is formed from a sub-portion of the upper part of the counter-doped zone 791. The third doped region 193 is formed by counter-doping renewal of the sub-region of the upper part of the counter-doped zone 791 by implantation with a dopant 471 of the conductivity type of the initial layer 730.

[0102] Figure 18 shows an ion beam modulation device 450 in the beam path of the ion beam for the second dopant 491 of Figure 15B. The ion beam modulation device 450 laterally modulates the ion beam such that in the second doped region 192, the lateral net dopant distribution drops continuously from a maximum net dopant concentration Nmax to a concentration Nmax / e, where e is the Euler number, within at least 200 nm (e.g., at least 500 nm).

[0103] The ion beam modulation device 450 may, for example, comprise a laterally structured energy filter having a substantially non-transmissive first portion 451 and a transmissive second portion 452. In the second portion 452, the energy and the angle of emergence of the ions are modulated depending on the impingement location such that the ion beam is split into partial beams extending between the energy filter and the SiC semiconductor substrate 700, with the ion density of each partial beam decreasing successively outwards.

[0104] According to another embodiment, the ion beam modulation device 450 includes a neutral graded mask, which is formed, for example, by temporarily heating the graded mask, the material of which sags slightly as a result of the heating. If the ion beam is directed at various angles through openings of sufficient height in the graded mask, lateral modulation of the ion beam also results.

[0105] Further embodiments of the semiconductor component are described in detail below. It will be appreciated that the features mentioned above, as well as those described below, may not only be used in the respective combinations shown, but also in other combinations or alone, without departing from the scope of the invention.

[0106] In some embodiments, the third doped region may be completely surrounded by each of the first and second doped regions, e.g., completely surrounded by each of the first and second doped regions. Additionally or alternatively, each of the first and second doped regions may completely surround the active region.

[0107] According to at least one embodiment, the dopant amount of the second doped region is greater than the dopant amount of the first doped region, for example, the dopant amount of the second doped region is at least twice as much as the dopant amount of the first doped region.

[0108] In some embodiments, the vertical extent of the edge termination structure is at least 80% and at most 100% of the distance between the bottom edge of the deeply doped region of the second conductivity type in the active area.

[0109] In some embodiments, the active area includes a further doped region of the second conductivity type, and the vertical extent of the edge termination structure is at least 80% of the distance between the deepest bottom end of the further doped region in the active area and the surface. The active area may further include at least one of the transistor cells with a gate electrode of the second conductivity type formed on the first surface.

[0110] In some embodiments, the vertical extent of the edge termination structure is at least 80% of the distance between the first surface and the bottom edge of the body region.

[0111] According to at least one embodiment, the semiconductor component includes a gate structure including a gate electrode and extending from the first surface into the SiC semiconductor body, where each body region may extend between two adjacent gate structures.

[0112] Additionally or alternatively, the transistor cell may include a shielding region of the second conductivity type. A distance between a bottom end of the shielding region and the first surface may be greater than a vertical extent of the gate structure. A vertical extent of the edge termination structure may be at least 80% of the distance between the first surface and the bottom end of the shielding region.

[0113] In some embodiments, the shield region overlaps vertically with the gate structure, hi alternative embodiments, the shield region may be laterally spaced apart from the gate structure.

[0114] According to at least one embodiment, the active area includes a continuous anode region of the second conductivity type adjacent the first surface. Alternatively, the active area includes a number of anode regions and channel portions of the drift region located between the anode regions. The channel portions may form a Schottky contact to the first loading electrode adjacent the first surface.

[0115] In some embodiments, the third doped region has a dopant concentration equal to the drift zone dopant concentration. Alternatively, or in combination, the third doped region includes a dopant of a second conductivity type, and the dopant concentration of the second conductivity type is equal to the dopant concentration of the first doped region. Alternatively, or in combination, the dopant amount of the first doped region is 2×10 12 cm -2 From 2 × 1013 cm -2 The range is.

[0116] In some embodiments, the dopant concentration of the second doped region is laterally constant. Alternatively, or in combination, the dopant concentration of the second doped region is at least 1×10 17 cm -3 It is.

[0117] According to at least one embodiment of the semiconductor component, the further doped region and / or the anode region comprises a highly doped sub-region, the dopant concentration of which may be equal to the dopant concentration of the second doped region.

[0118] According to at least one embodiment of the semiconductor component, the lateral width of the second doped region decreases moving away from the active region.

[0119] In some embodiments, the semiconductor component may include substructures. Each of the substructures may be formed from a second doped region and a third region adjacent to the second doped region. The third region may be adjacent to a side of the second region facing away from the active region. A width of each substructure may be constant.

[0120] Alternatively or in combination, the lateral net dopant concentration of the second doped region decreases from a maximum net dopant concentration Nmax to a concentration Nmax / e (e is Euler's number) within at least 200 nm (e.g., a lateral distance of at least 200 nm). For example, the lateral net dopant concentration decreases continuously and / or monotonically from Nmax to Nmax / e within a lateral distance of 200 nm.

[0121] The third doped region may be of the first conductivity type. Alternatively, the third doped region may be of the second conductivity type. In the latter case, the dopant concentration of the third doped region may be at most 50% of the dopant concentration of the second doped region and / or may be equal to the dopant concentration of the first doped region. [Explanation of symbols]

[0122] 100 SiC semiconductor body 101 First Surface 102 Second Surface 103 Side 104 Perpendicular 110 Source Region 120 Body Region 121 Main Area 125 Anode Region 130 Drift Structure 131 Drift Zone 136 Channel Part 137 Current diffusion zone 139 Contact Area 149 Contact area 150 Planar gate structure 151 Gate Dielectric 155 Conductive gate electrode 160 Shield Area 180 Mesa section 181 First Mesa Side 182 Second Mesa Side 190 Edge Termination Structure 191 First doped region 192 Second doped region 193 Third doped region 195 Substructure 210 Interlayer dielectric 310 first load electrode 316 Trench Contact 320 Second Loading Electrode 400 Polyimide structure 401 line 402 line 450 Ion Beam Modulator 451 First Part 452 Second Part 480 First Implantation Mask 481 First Dopant 485 Aperture 490 Second Implantation Mask 491 Second Dopant 495 Aperture 500 Semiconductor parts 601 Element Structure 610 Central Active Area 690 Edge Termination Area 701 1st main surface 725 Partial layer 730 Initial layer 761 Background Doping 762 Dopant Concentration 763 Net Dopant Concentration 791 Reverse Dope Zone 902 forming a counter-doped zone in the initial layer of the SiC semiconductor substrate 904 forming a second doped region of a second conductivity type

Claims

1. A semiconductor component, The present invention relates to a SiC semiconductor body having an active area and an edge termination structure at least partially surrounding the active area, the edge termination structure comprising: a drift zone of a first conductivity type formed within the SiC semiconductor body; a first doped region (191) of a second conductivity type between a first surface (101) of the SiC semiconductor body (100) and the drift zone (131), the first doped region (191) at least partially surrounding the active area (610) and spaced apart from the first surface (101); a plurality of second doped regions (192) of the second conductivity type between the first surface (101) and the first doped region (191); a third doped region (193) of the first conductivity type located laterally between the second doped regions (192); Including, the dopant amount of the second doped region (192) is higher than the dopant amount of the first doped region (191), and the innermost second doped region (192) is located inside the innermost third doped region (193); Semiconductor components.

2. Each of the third doped regions (193) is completely surrounded by the first doped region (191) and the second doped region (192). The semiconductor component according to claim 1 .

3. a vertical extent (v1) of the edge termination structure (190) is at least 80% and at most 100% of the distance between a bottom end of the deepest doped region of the second conductivity type in the active area (610) and the first surface (101); The semiconductor component according to claim 1 or 2.

4. the active area (610) further comprises a fourth doped region (120, 160) of the second conductivity type, and the vertical extent (v1) of the edge termination structure (190) is at least 80% of the distance between the deepest bottom end of the fourth doped region (120, 160) of the active area (610) and the first surface (101); A semiconductor component according to any one of claims 1 to 3.

5. The active area (610) includes a transistor cell (TC) including a body region (120) of the second conductivity type; the vertical extent (v1) of the edge termination structure (190) is at least 80% of the distance (v3) between the first surface (101) and a bottom edge of the body region (120); The semiconductor component according to claim 4.

6. The active area (610) includes a transistor cell (TC) including a body region (120) of the second conductivity type; The transistor cell (TC) includes a shielding region (160) of the second conductivity type, and a distance (v4) between a lower end of the shielding region (160) and the first surface (101) is greater than a vertical extent (v2) of the gate structure (150); A semiconductor component according to any one of claims 1 to 5.

7. the vertical extent (v1) of the edge termination structure (190) is at least 80% of the distance (v4) between the first surface (101) and a lower end of the shielding region (160); The semiconductor component according to claim 6.

8. The active area (610) includes a plurality of anode regions (125) and a plurality of channel portions (136) of a drift structure (130) between the anode regions (125); the channel portion (136) is adjacent to the first surface (101) and forms a Schottky contact (SC) to a first loading electrode (310); A semiconductor component according to any one of claims 1 to 5.

9. a dopant concentration of the third doped region (193) equal to a dopant concentration of the drift zone (131); A semiconductor component according to any one of claims 1 to 8.

10. The dopant amount of the first doped region (191) is 2×10 １２ cm －２ From 2 x 10 １３ cm －２ and / or the dopant concentration of the second doped region (192) is at least 1×10 １７ cm －３ That is, A semiconductor component according to any one of claims 1 to 9.

11. a dopant concentration is laterally constant within said second doped region (192); A semiconductor component according to any one of claims 1 to 10.

12. a fourth doped region (120, 160) in the active region (610) comprising a heavily doped subregion (149), the dopant concentration of the heavily doped subregion (149) being equal to the dopant concentration of the second doped region (192); A semiconductor component according to any one of claims 1 to 3.

13. the plurality of anode regions (125) in the active region (610) includes a heavily doped subregion (149), the dopant concentration of the heavily doped subregion (149) being equal to the dopant concentration of the second doped region (192); A semiconductor component according to any one of claims 1 to 5.

14. a lateral width (w2) of the second doped region (192) decreases as the distance from the active region (610) increases; A semiconductor component according to any one of claims 1 to 13.

15. a plurality of substructures, each of the substructures being formed from a second doped region (192) and a third doped region (193), the third doped region (193) adjacent to the second doped region (192) on a side facing away from the active region (610); The width (ws) of the substructure is constant; A semiconductor component according to any one of claims 1 to 14.

16. The present invention relates to a SiC semiconductor body having an active area and an edge termination structure at least partially surrounding the active area, the edge termination structure comprising: a first conductivity type drift zone formed within the SiC semiconductor body; a first doped region (191) of a second conductivity type between a first surface (101) of the SiC semiconductor body (100) and the drift zone (131), the first doped region (191) at least partially surrounding the active area (610) and spaced apart from the first surface (101); a plurality of second doped regions (192) of the second conductivity type between the first surface (101) and the first doped region (191); a third doped region (193) of the second conductivity type between adjacent second doped regions (192) of the plurality of second doped regions (192); Including, the dopant concentration of the second doped region (192) is higher than the dopant concentration of the third doped region (193); the lateral net dopant concentration of the second doped region (192) decreases continuously within a lateral distance of at least 200 nm from a maximum net dopant concentration Nmax to a concentration Nmax / e, where e is Euler's number; Semiconductor components.

17. the third doped region (193) is of the second conductivity type and the dopant concentration of the third doped region (193) is at most 50% of the dopant concentration of the second doped region (192); 17. A semiconductor component according to claim 16.

18. the third doped region (193) is of the second conductivity type and a dopant concentration of the third doped region (193) is equal to a dopant concentration of the first doped region (191); 17. A semiconductor component according to claim 16.

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