Manufacturing method for electronic semiconductor parts

Abstract

A method for manufacturing an electronic semiconductor component is provided. The method includes the steps of doping a first layer (21) of SiC in a donor substrate (12) by ion implantation, creating a predetermined damage site (26) in the donor substrate (12), and creating a connection between the donor substrate (12) and an acceptor substrate (28). The first layer (21) is disposed in a region between the acceptor substrate (28) and a remaining portion (22) of the donor substrate (12). Finally, the donor substrate (12) is divided in the region of the predetermined damage site (26) to create a preprocessed composite substrate (18). The preprocessed composite substrate (18) includes an acceptor substrate (28) and a doped layer (32) connected thereto, and includes at least a first section of the first layer (21) of the donor substrate (12). In addition, the implantation defects are repaired by laser irradiation (43) during the process.

Description

[Technical field]

[0001] The present invention relates to a method for manufacturing electronic semiconductor components.

[0002] Discrete high-blocking power semiconductor components with nominal blocking voltages above 600V are usually built vertically in both silicon and SiC. What this means for diodes, i.e. MPS (merged PIN Schottky) diodes, Schottky diodes or pn diodes, is that the cathode is located on the front side of the substrate and the anode on the back side of the substrate. A similar configuration can be applied in the case of vertical power MOS (metal-oxide-semiconductor) components. The gate and source electrodes are on the front side of the substrate and the drain electrode is on the back side of the substrate. In conventional power MOSFETs, the actual transistor element and / or channel region can be located parallel to the surface (D-MOS) or perpendicular to the surface (trench MOS). For SiC MOSFETs, such as trench transistors, special designs have been established.

[0003] Depending on the required blocking capability (reverse blocking voltage) the width of the drift region (= active area, voltage absorbing layer) is set. For example, the width of the drift zone of a 600V MOSFET component in silicon will be about 50μm.

[0004] In the case of so-called superjunction components, the width of the voltage absorption layer may be somewhat narrower compared to "simple" vertical MOSFETs. A special feature of this type of vertical components is that the drift is characterized by alternating vertical p-doped and n-doped columns. The additionally introduced p-doping compensates, in case of blocking, for the increase in the charge of the n-doped regions, which determines the resistance between the source and drain electrodes in the switched-on state. Thus, with a comparable blocking capability, the on-state resistance can be reduced by up to about a factor of 10 compared to conventional vertical MOS transistors. The actual transistor element, i.e. the channel region, can be arranged in superjunction MOSFET architectures parallel to the surface (D-MOS) or perpendicular to the surface (Trench MOS).

[0005] The special material properties of SiC require the provision of specific manufacturing methods and the application of specific architectures of the channel and transistor regions of vertical power semiconductor components.

[0006] Usually, the active zone of all vertical power diodes or all power transistors (MOSFETs and J-FETs) is formed in a single crystalline epitaxial layer. These epitaxial layers are built or deposited on a crystalline carrier wafer. Thus, the doping and the vertical extent (thickness) of the active epitaxial zone can be adapted to the respective blocking voltage, and the highly doped carrier wafer can be optimized with respect to its doping to minimize its contribution to the on-state resistance.

[0007] Particularly in the case of SiC substrates, the production of the above-mentioned layer structures is complex and costly due to the high costs involved in the deposition of the epitaxial layers and further in the preparation of the monocrystalline carrier wafer.

[0008] DE 10 2019 112 985 A1 proposes as an alternative to producing semiconductor components without epitaxial deposition by cleaving off a substrate from a SiC wafer and subsequently ion implanting it in a drift zone using an energy filter.

[0009] The present invention aims to provide a method for manufacturing electronic semiconductor components which reduces complexity and costs.

[0010] This object is achieved by the features of claim 1 or claim 51. Advantageous embodiments are the subject matter of the dependent claims.

[0011] According to a first aspect, a method according to the invention for manufacturing an electronic semiconductor component (50) via the intermediate step of creating a preprocessed composite substrate (18), the preprocessed composite substrate (18) comprising an acceptor substrate (28) and a first section (48) of a donor substrate (12), the first section comprising at least one doped layer (32), comprises: a) providing a donor substrate comprising single crystal SiC; b) doping the entire first layer of the donor substrate by ion implantation, during doping a predetermined dopant depth profile is created in the first layer of the donor substrate, the first layer extending from an outer surface of the donor substrate facing the ion beam to a predetermined doping depth adjacent the remaining part of the donor substrate, and during doping implantation defects are created; c) creating a predetermined fracture site in the donor substrate, the fracture site extending substantially parallel to an outer surface of the donor substrate; d) providing an acceptor substrate and creating a bonded connection between the donor substrate and the acceptor substrate, the first layer being disposed in an area between the acceptor substrate and the remainder of the donor substrate; e) splitting the donor substrate in the region of the predetermined breakage site to create a pre-processed composite substrate, the pre-processed composite substrate comprising an acceptor substrate and a first section of the donor substrate connected thereto, the first section having at least one doped layer, the doped layer constituting at least one section of the first layer of the donor substrate, the splitting being performed such that the first section of the donor substrate has a first surface in the region of the predetermined breakage site, the first surface being on an opposite side of the composite substrate to the acceptor substrate; f) introducing at least one further, preferably a plurality of further structural elements of the semiconductor component (50) from the first surface (58) into the composite substrate (18) and / or arranging at least one further, preferably a plurality of further structural elements of the semiconductor component (50) on the first surface (58); wherein after at least one of steps b), c), e) and f), of which preferably after step e) and / or after or during step f), a repair step of implantation defects is performed in the first layer (21) of the donor substrate (12) and / or in the first section (48) of the donor substrate (26) by laser irradiation (43).

[0012] The repair step by laser irradiation is preferably carried out after step e) and / or after or during step f). In this case it is possible to use an acceptor substrate that does not need to be resistant to high temperatures, for example a substrate made of silicon. During step f), it is meant that also certain structural elements of the semiconductor component, whose manufacture does not require ion implantation, can be created or applied after the repair.

[0013] A repair step by laser irradiation is preferably carried out on the first surface of the composite substrate after step e) and / or after or during step f).

[0014] After step e) and / or during the repair step by laser irradiation after or during step f), the temperature in the region of the acceptor substrate preferably does not exceed 1500°C, more preferably 1450°C, even more preferably 1400°C and particularly preferably does not exceed 1350°C.

[0015] After step e) and / or during the repair step by laser irradiation after or during step f), a temperature gradient is preferably created in the composite substrate, the temperature close to the first surface being higher than in the acceptor substrate.

[0016] The temperature of the doped layer after step e) and / or after or during step f) during the repair step by laser irradiation is preferably at least temporarily at 1400°C, more preferably at least 1450°C, particularly preferably at least 1500°C.

[0017] In one embodiment, the predetermined damage site is in an area of ​​the remaining part of the donor substrate, and further, after step e) and before the repair step, a further step of performing ion implantation is performed, preferably using an energy filter, from the first surface of the composite substrate, whereby an auxiliary doped layer is formed.

[0018] The ion implantation into the composite substrate preferably extends here at least as far as the doped layer.

[0019] Ion implantation into the composite substrate is preferably carried out so that the doping concentration of the auxiliary doped layer is higher than in the region of the doped layer facing the auxiliary doped layer, preferably 1.5 to 100 times higher, particularly preferably 2 to 10 times higher.

[0020] The temperature of the auxiliary doped layer after step e) and / or after or during step f) during the repair step by laser irradiation is preferably at least temporarily at 1400°C, more preferably at least 1450°C, particularly preferably at least 1500°C.

[0021] Alternatively or additionally, a repair step by laser irradiation can be carried out after at least one of steps b) and c).

[0022] A repair step by laser irradiation after at least one of steps b) and c) is preferably performed on the outer surface of the donor substrate.

[0023] During at least one subsequent laser irradiation repair step of steps b) and c), the temperature in the region of the remaining part of the donor substrate preferably does not exceed 1500°C, more preferably 1450°C, even more preferably 1400°C, and particularly preferably 1350°C.

[0024] During a subsequent laser repair step of at least one of steps b) and c), a temperature gradient is preferably created in the donor substrate, with the first layer having a higher temperature than the remainder of the donor substrate.

[0025] The temperature of the first layer during the repair step by laser irradiation after at least one of steps b) and c) is preferably at least temporarily 1400°C, more preferably at least 1450°C, particularly preferably at least 1500°C.

[0026] The repair step is preferably carried out by the introduction of generally pulsed light, preferably depositing a large number of individual pulses per irradiation point, particularly preferably a number between 100 and 5000 individual pulses.

[0027] Generally, it is also preferred that during the repair step, temperature introduction into depth and / or temperature gradients are controlled by sequential or simultaneous application of light of different wavelengths, pulse durations and / or pulse numbers.

[0028] Moreover, the pulse frequency is preferably within the range of 20 Hz to 3 kHz, and more preferably between 30 Hz and 1 kHz.

[0029] In one preferred embodiment, the pulse width is in the range of 1 to 1000 ns.

[0030] The wavelength of the light is preferably within the range of 250 to 400 nm.

[0031] Very generally, within the scope of the present invention, a repair step can be performed immediately after the completion of each ion implantation, or implantation defects of multiple successive ion implantations can be repaired simultaneously in one repair step. The donor substrate can also be repaired by an equilibrium process (e.g., in a furnace), where the entire donor substrate is heated to a temperature above 1400°C, or above 1450°C, or above 1500°C.

[0032] Overall, therefore, a single repair step according to the invention by laser irradiation can be provided (applied to either the donor substrate or the composite substrate), two repair steps according to the invention by laser irradiation can be provided (applied to the donor substrate and the composite substrate, or in each case only one of the two), or three or more repair steps according to the invention by laser irradiation can be provided (applied to the donor substrate and the composite substrate, or in each case only one of the two).

[0033] When the repair process according to the invention is applied to a composite substrate, the composite substrate may already be fully or partially repaired, or may not yet be repaired at all.

[0034] The fabrication of source and body regions, channel regions, shield structures, J-FET structures, connecting contacts, edge finishing, etc. can be performed by ion implantation. The dopings can be p-type or n-type and can be superimposed or introduced alone. A suitable mask (lithography) is preferably provided. Typical energies of the implantation steps are from a few keV up to about 1 MeV. The implantation steps are preferably performed at room temperature or at temperatures between 500 °C and 1000 °C. During the introduction of the base doping or parts of the base doping after the construction of the composite substrate, the ion energies can reach up to 30 MeV.

[0035] Repair of ion implantation defects (including defects originally present in the composite material at the time of preparation) is accomplished by laser repair or light of appropriate wavelength and intensity. The appropriate wavelength is one that ensures sufficient penetration depth and ensures energy absorption.

[0036] Depending on the depth of the area to be repaired, wavelengths whose energy is greater than the band gap (highly absorptive and shallow, i.e. energy absorption occurs over a narrow depth range) or smaller than the band gap (highly transmissive and energy absorption occurs over a wide depth range) are used.

[0037] The temperature introduction or temperature gradient at depth can be controlled by sequential or simultaneous irradiation with light of different wavelengths, pulse durations, and / or number of pulses.

[0038] The energy input can be further controlled by pulse width modulation and modulation of the power density per pulse, as well as the temporal sequence of the pulses. Thus, for example, a temporal fine structure with rapid double or multiple pulses followed by a long pause is conceivable. For example, the pulse width is 50 ns, the double pulses are in the kHz range, and the pauses are in the range of a few Hz.

[0039] The pulse width can range from picoseconds to milliseconds, but is preferably in the range of 1-1000 nanoseconds. The pulse frequency can range from a few Hertz to a few kilohertz, for example 50 Hz. Using the aforementioned parameters opens up a very large parameter space.

[0040] Repair can occur either in a "sub-molten state", i.e., unmolten, or in a "fully molten state", i.e., molten.

[0041] The irradiation process is preferably performed in pulses to prevent excessive heating of the acceptor substrate.

[0042] Preferably, multiple individual pulses are deposited per hit point so that the desired amount of energy is deposited in the material per hit point.

[0043] Laser repair is preferably a continuous process, for example using a pulsed excimer laser (e.g., 308 nm or 355 nm wavelength) with pulse lengths in the picosecond to nanosecond range. Typically, each point is occupied with, for example, hundreds or thousands of laser pulses, and the wafer is scanned sequentially.

[0044] The laser annealing process is preferably carried out under a protective gas atmosphere.

[0045] The laser annealing process is preferably performed after depositing a thin capping layer. The capping layer is composed of a carbonaceous material or a silicon-containing material. The capping layer may be chemically or physically modified (melted) during the laser annealing process. The capping layer is removed after the laser annealing step. The capping layer is thin, typically between 20 nm and 500 nm.

[0046] It should be noted that further process steps, such as layer deposition, further implants or etching, may also occur between each implant step and each repair step. In general, the implant and repair steps do not have to directly follow each other. A single repair step may also repair multiple individual implants.

[0047] The first layer is always composed of single crystal SiC. Preferably, the donor substrate is entirely composed of single crystal SiC.

[0048] The thickness of the first layer is preferably 3 to 15 μm, since ion implantation can be reasonably carried out over a thickness of this order.

[0049] In one preferred embodiment, the donor substrate is a crystal made of high quality single crystal semi-insulating SiC material with high purity. In particular, it is free of elemental contaminants, especially N, B, P, with concentrations mainly below 5E15 cm -3 In this context, "predominantly" means that the criterion applies almost everywhere in the course of the depth profile, but deviations may exist in certain regions, for example at the surface. In this case, this is preferably a HT-CVD (High Temperature Chemical Vapor Deposition) material.

[0050] In one preferred embodiment, the donor substrate is made of 4H, 6H, or 3C polytypes of SiC, which have proven advantageous for the manufacture of semiconductor components.

[0051] The outer surface of the donor substrate facing the ion beam preferably deviates from a direction perpendicular to the ion beam to the c-direction of the crystal structure of the donor substrate by less than 0.5°, more preferably less than 0.3°, even more preferably less than 0.1°, and most preferably not at all. An advantage of about 0° is, among other things, that the donor substrate can be cut parallel to the outer surface, so that more partial wafers can be obtained from the cylinder.

[0052] The donor substrate preferably has a thickness of more than 100 μm, preferably more than 200 μm, more preferably more than 300 μm, up to 15 cm, preferably up to 10 cm.

[0053] Typically, the doping of the first layer is such that the doping concentration in the first layer is 1E15 cm -3 ~5E17cm -3 It is preferred to provide a p-doping or n-doping with a concentration of 0.1 - 0.15. This doping concentration is very suitable for the drift zone (active layer, power absorption layer) of many high performance components. The doping may be constant over the thickness of the first layer or may show a doping profile deviating therefrom.

[0054] The doping of the first layer is preferably carried out using ions of one of the elements nitrogen, phosphorus, boron or aluminium.

[0055] The primary energy range of the ion beam during doping of the first layer is preferably between 1 MeV and 30 MeV, and under certain circumstances up to 50 MeV.

[0056] In one preferred embodiment, the doping of the first layer provides a constant or substantially constant dopant depth profile. These should be understood as profiles that deviate from a completely flat dopant depth profile by less than 20%, preferably less than 10%. In practice, the plateau is flanked by descending flanks, i.e. the decline of the profile is not vertical or steep in the region of the doping depth.

[0057] In an alternative embodiment, the doping of the first layer provides a dopant depth profile that descends stepwise from the outer surface of the donor substrate facing the ion beam, where the step is formed in a surface proximal region of the first layer facing the ion beam and has a depth towards the ion beam in the range of up to 40%, preferably up to 30%, of the total depth of the first layer.

[0058] The concentration difference between the highest and lowest step is preferably at least 10-fold, preferably at least 100-fold, more preferably at least 500-fold, especially preferably at least 1000-fold.

[0059] Here, the depth extent of the side regions of the step exceeds the depth extent of the stepped plateau.

[0060] In an alternative embodiment, the doping of the first layer provides a dopant depth profile that falls continuously from the outer surface of the donor substrate facing the ion beam.

[0061] Here, the continuously falling dopant depth profile is preferably a profile according to the following formula: TIFF2024528579000002.tif24164, where D max is the maximum doping concentration, α is a value between 10 and 10,000. z is the distance to the outer surface, b is the thickness of the first layer, f is the tolerance factor between 0.95 and 1.05, D0 is the background doping, Where: TIFF2024528579000003.tif14164, where E max is the maximum field, ε r is the dielectric constant of the semiconductor, ε0 is the dielectric constant in a vacuum, e0 is the elementary charge of an electron, V br is the breakdown voltage, And here, TIFF2024528579000004.tif16164

[0062] Generally, a further step of creating a contact layer in the surface region of the first layer or applying a contact layer to the outer surface of the first layer is preferred, whereby a bonded connection between the donor substrate and the acceptor substrate is generated via the contact layer. In this case, the sequence is: acceptor substrate, contact layer, remaining part of the first layer or first layer, remaining part of the donor substrate. Thus, a particularly good low-resistance connection between the donor substrate and the acceptor substrate can be ensured.

[0063] The creation of the contact layer is preferably carried out by ion implantation.

[0064] The dopant concentration of the contact layer is preferably at least 100 times, preferably at least 1000 times, more preferably at least 10,000 times, even more preferably at least 100,000 times higher than the average dopant concentration of the remainder of the first layer or the first layer. In this way, the lowest possible resistance mating connection is achieved and the penetration of electric fields into interfaces within the semiconductor component is avoided.

[0065] In one preferred embodiment, the dopant concentration in the contact layer is 1E17 cm -3 Larger, preferably 1E19cm -3 Greater than.

[0066] The predetermined damage site is preferably in a region of the first layer, particularly preferably in an edge region of the first layer close to the predetermined doping depth, particularly preferably less than 1 μm in the edge region, in this way as little doped material as possible remains on the donor substrate after splitting.

[0067] In an alternative embodiment, the predetermined damage site is in the region of the remaining part of the donor substrate, and further after step e) a further step is performed of performing ion implantation from the side into the composite substrate in the semiconductor component. This has the advantage that active zones with a larger total thickness can be formed. The superposition of two different implants thus made possible can also create different preferred doping profiles or even stepwise create the preferred doping profile.

[0068] Within this alternative embodiment, ion implantation into the composite substrate preferably provides a dopant depth profile of the auxiliary doped layer that extends at least to the doped layer.

[0069] Ion implantation into the composite substrate can be performed such that the combined dopant depth profile of both the doped and auxiliary doped layers is, for example, a constant profile, a stepwise increasing profile towards the acceptor substrate, or a continuous increasing profile towards the acceptor substrate, although other profile shapes are also contemplated.

[0070] Here, the obliquely descending flanks may overlap in the transition region of the two dopant depth profiles of the doped layer and the auxiliary doped layer.

[0071] Particularly preferred are embodiments in which the doping concentration in the auxiliary doped layer is higher than in the region of the doped layer facing the auxiliary doped layer, preferably 1.5 to 100 times higher, particularly preferably 2 to 10 times higher. Here too, the doping concentration in the doped layer can have a constant profile, a profile that increases stepwise towards the acceptor substrate or a profile that increases continuously towards the acceptor substrate.

[0072] The creation of the predetermined damage site is preferably carried out by ion implantation of splitting trigger ions.

[0073] The split trigger ions are preferably introduced across the entire width of the donor substrate in order to produce a split surface that is as uniform as possible.

[0074] Alternatively, split trigger ions can be introduced over only a portion of the width of the donor substrate, which reduces the effort during ion implantation.

[0075] The split trigger ions are preferably now only introduced in the edge region of the donor substrate.

[0076] In a preferred embodiment, the split trigger ion is selected from hydrogen (H or H2), helium (He), and boron (B).

[0077] In principle it is advantageous if the split trigger ion is an energetic ion having an energy between 0.5 and 10 MeV, preferably between 0.5 and 5 MeV, more preferably between 0.5 and 2 MeV.

[0078] The particle dose of the split trigger ion is 1E15 cm in each case. -2 and 5E17cm -2 Preferably, the dose is between 0.01 and 0.15, at which reliable resolution is achieved.

[0079] The energy sharpness (ΔE / E) of the primary ion beam of the split trigger ion is preferably 10 -2 Less than 10, more preferably -4 In this way, it is ensured that a given damage site has a minimum thickness and that the ion energy loss peak at the given damage site is as sharp as possible.

[0080] Splitting of the donor substrate is preferably caused by a temperature treatment of the composite substrate at a temperature between 600° C. and 1300° C., preferably between 750° C. and 1200° C., more preferably between 850° C. and 1050° C. Alternatively, mechanical methods are also conceivable.

[0081] Alternatively, the division of the donor substrate can be performed by other division methods, for example laser division methods.

[0082] In a preferred embodiment, the production of the adhesive connection is carried out by temperature treatment of the composite substrate at temperatures between 800 and 1400°C, preferably between 900 and 1300°C.

[0083] To simplify the process, it is conceivable that both the creation of the bonding connections and the splitting of the donor substrate are performed by temperature treatments, performing both steps simultaneously.

[0084] Preferably, a pre-treatment, in particular a wet chemical, plasma or ion beam treatment, of at least one, preferably both, surfaces to be bonded is carried out prior to the step of creating the bonded connection.

[0085] The acceptor substrate is preferably only stable at temperatures up to 1400°C, preferably up to 1350°C, particularly preferably up to 1300°C.

[0086] In one preferred embodiment, the acceptor substrate is formed from silicon.

[0087] The doping in step b) is preferably carried out using an energy filter, which is a microstructured film having a predetermined structural profile for setting the dopant depth profile induced by the implantation in the first layer of the donor substrate. The same applies to all other ion implantations carried out during the method. Other types of ion implantation are, for example, chain or channeling implantations.

[0088] Preferably, a post-treatment of the surface of the composite substrate is carried out in the area of ​​the predetermined breakage sites after the splitting step, in particular by grinding or polishing and / or removing (surface-close) defects, in which case chemical-mechanical polishing is particularly advantageous.

[0089] The connection between the donor substrate or doped layer and the acceptor substrate can be permanent or temporary: in the latter case, the acceptor substrate is removed again after partial or complete processing of the semiconductor component.

[0090] According to a further aspect, a method for producing an electronic semiconductor component according to the invention comprises the steps of: providing a pre-processed composite substrate, the pre-processed composite substrate having an acceptor substrate and at least one fully doped layer of SiC bonded to the acceptor substrate, the doped layer (32) preferably having a thickness of between 3 μm and 30 μm; and repairing the implantation defects in the doped layer by laser irradiation, wherein the doped layer is substantially completely free of implantation defects and the temperature in the region of the acceptor substrate does not exceed 1500°C, preferably 1450°C, more preferably 1400°C, and especially preferably 1350°C.

[0091] In this case, it is initially irrelevant which method the pretreated composite substrate or the doped layer was created in. In addition to the above-mentioned method steps, for example, heterotactic deposition of 3C SiC material onto an acceptor substrate is also considered. With regard to this aspect, the fact that the doped SiC layer can be substantially completely free of defects, while the temperature of the more sensitive acceptor substrate is significantly lower, is relevant within the scope of the present invention.

[0092] Again, the doped layer preferably has a first surface opposite the acceptor substrate, and the laser irradiation is preferably performed on the first surface.

[0093] During the laser repair process, a temperature gradient is preferably created within the composite substrate, with the temperature adjacent the first surface being higher than in the acceptor substrate.

[0094] The temperature of the doped layer during the repair step by laser irradiation is at least temporarily at least 1400°C, preferably at least 1450°C, particularly preferably at least 1500°C.

[0095] The preferred details of the repair step (eg, introduction of pulsed light, wavelength, pulse frequency, pulse width, etc.) are the same as those described above.

[0096] The acceptor substrate is preferably only stable at temperatures up to 1400°C, preferably up to 1350°C, particularly preferably up to 1300°C.

[0097] It is particularly preferred here if the acceptor substrate is also made of silicon.

[0098] The electronic semiconductor components are generally preferably vertical semiconductor components, and more preferably high blocking vertical power semiconductor components.

[0099] Examples of structural elements include active and passive regions of different doping (source, J-FET p-doped gate structure, MOSFET channel, shield region, pn transition, resurface edge region, source-gate contact region, J-FET channel region), insulating oxide, gate oxide, contact region (metal, silicide), Schottky contact (metal, alloy), ohmic contact, source-gate metallization or wiring, passivation layer, trench for gate electrode, bond pad, contact hole or contact trench. [Brief description of the drawings]

[0100] FIG. 1 is a schematic cross-sectional view of a first embodiment of a donor substrate that can be used in the method according to the invention.

[0101] FIG. 2 is a schematic diagram of an irradiation apparatus having an energy filter for irradiating a donor substrate.

[0102] FIG. 3 is a schematic diagram of the mode of operation of an energy filter that can be used in the method according to the invention.

[0103] FIG. 4 is a schematic diagram of various doping profiles that can be produced by energy filters of different configurations.

[0104] FIG. 5 shows a schematic diagram of the doping sequence of the first layer of the donor substrate and the resulting doping profile of the donor substrate.

[0105] FIG. 6 shows various possibilities for the doping profile of the first layer of the donor substrate.

[0106] FIG. 7a illustrates diagrammatically the creation or application of a contact layer on a donor substrate.

[0107] FIG. 7b shows a schematic of the repair step on the donor substrate.

[0108] FIG. 8 shows a schematic representation of a first variant of creating a predetermined damage site in a donor substrate.

[0109] FIG. 9 shows a schematic representation of a second variant for creating a predetermined damage site in a donor substrate.

[0110] FIG. 10 illustrates a schematic of creating a bonded connection between a donor substrate and an acceptor substrate.

[0111] FIG. 11 shows a schematic diagram of separation of the remaining portion of the donor substrate from the composite substrate.

[0112] FIG. 12 shows diagrammatically the post-treatment of the surface of the composite substrate in the region of the division points.

[0113] FIG. 13a illustrates a schematic cross-section of one embodiment of a pre-processed composite substrate.

[0114] FIG. 13b shows a schematic of a repair step on a composite substrate.

[0115] FIG. 14 illustrates a cross-sectional view and associated doping profile of a further embodiment of a pre-processed composite substrate.

[0116] FIG. 15 is a schematic diagram of the division of a wafer rod that serves as a donor substrate when used to create multiple composite substrates from the donor substrate.

[0117] FIG. 16 shows a schematic diagram of a doping sequence of a first layer of a donor substrate using masking in some regions of the donor substrate and alternative doping profiles of the donor substrate resulting therefrom.

[0118] FIG. 17 shows a schematic cross-section of an exemplary basic structure of a semiconductor electronic component manufactured using a manufacturing method according to the invention.

[0119] FIG. 18 shows a schematic cross-section of another exemplary base structure of an electronic semiconductor component manufactured using a manufacturing method according to the present invention.

[0120] FIG. 19 shows a schematic cross-section of an embodiment of an electronic semiconductor component in the form of a planar MOS transistor.

[0121] FIG. 20 shows a schematic of a preferred doping profile for an electronic semiconductor component.

[0122] The method according to the invention for manufacturing an electronic semiconductor component starts, according to a first embodiment, with the provision of a donor substrate 12 comprising or consisting entirely of monocrystalline silicon carbide (SiC) (see Figures 1 and 2).

[0123] The embodiment of the donor substrate 12 shown in Figure 1 is a wafer made of high quality semi-insulating SiC material with high purity. In particular, it has a concentration of elemental contaminants such as N, B, P of 5E15 cm -3 It should be understood as a material that is less than 0.5 mm thick. The main meaning in this context is that the criterion applies almost everywhere in the course of the depth profile, but deviations may exist in certain areas, such as the surface. Particularly preferred are HT-CVD (High Temperature Chemical Vapor Deposition) materials.

[0124] The donor substrate 12 according to Figure 1 preferably has a thickness of more than 100 μm, preferably more than 200 μm, more preferably more than 300 μm, up to 15 cm, preferably up to 10 cm, and can in particular be formed as an undoped or weakly n-doped wafer rod (see Figure 15).

[0125] In one preferred embodiment, the donor substrate is made of 4H, 6H, or 3C polytypes of SiC, which have proven to be advantageous for the properties of the semiconductor components manufactured therewith.

[0126] After the donor substrate 12 is prepared, a doping (see FIG. 5) of a first layer 21 in the donor substrate 12 is performed, which will at least later assume or partially assume the function of the drift zone (also called active zone or voltage absorption zone) of the finished component. This doping of the first layer 21 of the donor substrate 12 is carried out by ion implantation using an energy filter 20. The corresponding basic structure is shown in FIG.

[0127] 2 shows an irradiation chamber 8, in which a high vacuum typically exists. The donor substrate 12 to be doped is accommodated in a substrate holder 30 within the irradiation chamber 8.

[0128] An ion beam 10 is generated by a particle accelerator (not shown) and directed into irradiation chamber 8, where the energy of ion beam 10 is dispersed by an energy filter 20 and incident on a donor substrate 12 to be irradiated. Alternatively, the energy filter 20 can be located within the irradiation chamber 8 or directly adjacent to the irradiation chamber 8 in a separate vacuum chamber that can be closed using a valve.

[0129] The substrate holder 30 does not have to be stationary, but rather can optionally be provided with a device for displacing the donor substrate 12 in xy (in a plane perpendicular to the sheet surface). Furthermore, a wafer wheel is considered as the substrate holder 30, on which the donor substrate 12 to be implanted is fixed and which rotates during implantation. It is also possible to displace the substrate holder 30 in the beam direction (z direction). Furthermore, the substrate holder 30 can be provided with a heater or cooler, if necessary.

[0130] The basic principle of the energy filter 20 is illustrated in FIG. 3. A monoenergetic ion beam 10 changes its energy as a function of the position of incidence while passing through the energy filter 20, designed as a microstructured membrane. The resulting energy distribution of the ions of the ion beam 10 modifies the depth profile of the implanted material in the matrix of the donor substrate 12. E1 denotes the energy of the first ion, E2 the energy of the second ion, conc denotes the doping concentration and d denotes the depth in the donor substrate 12. A typical Gaussian distribution is identified by reference A on the right side of the figure, which occurs without the use of the energy filter 20. In contrast to this, a rectangular distribution is depicted as an example with reference B, which can be achieved with the use of the energy filter 20.

[0131] The layout or three-dimensional structure of the energy filter 20 shown in Fig. 4 shows the basic possibilities for creating a large number of dopant depth profiles by means of the energy filter 20. conc again denotes the doping concentration and d again denotes the depth in the donor substrate 12. The filter structure profiles can in principle be combined with each other to obtain new filter structure profiles and thus new dopant depth profiles.

[0132] Such energy filters 20 are generally manufactured from silicon. They have a thickness between 3 μm and 200 μm, preferably between 5 μm and 50 μm, particularly preferably between 7 μm and 20 μm. They can be held in a filter frame (not shown). The filter frame can be exchangeably accommodated in a filter holder (not shown).

[0133] For the preferred formation of an n-doped first layer 21, implantation using nitrogen or phosphorus ions is particularly suitable, while for a p-doped layer implantation using boron or aluminum ions is particularly suitable.

[0134] In an exemplary embodiment of the method step of doping the first layer 21 shown in FIG. 5, ion implantation into the donor substrate 12 is performed from the front side of the donor substrate 12. The face of the donor substrate 12 facing the ion beam is hereafter referred to as the outer face 23. The short solid black arrows indicate ions of minimum energy passing through the energy filter 20, and the long solid black arrows indicate ions of maximum energy passing through the energy filter 20. The resulting doping profile along the cross section A-A' is shown on the right side of the coordinate system. conc represents the doping concentration. The doping profile is based on the design of the donor substrate 12 according to FIG. 1 and is approximately uniform throughout the first layer 21. The first layer 21 extends from the outer face 23 of the donor substrate 12 facing the ion beam 10 to a predetermined doping depth (T), where the remaining part 22 of the donor substrate 12 is adjacent and is not affected by the ion implantation by the energy filter.

[0135] The thickness of the first layer 21 preferably corresponds substantially to a pre-determined thickness of the active layer, or the combination of the active layer and the field stop layer, or the combination of the active layer, the field stop layer and the surface functional zone in the subsequent component. The total thickness of the first layer 21 is therefore determined by the type of semiconductor component to be manufactured and, in particular, by the voltage class. The higher the voltage class, the thicker the first layer 21. For particularly high voltage classes, see FIG. 14 and the associated description.

[0136] The thickness of the first layer 21 is preferably between 3 and 15 μm, which corresponds to the currently reasonable possible doping depth T of the above-mentioned preferred ion types in SiC.

[0137] 6a to 6c show possible preferred doping profiles in the first layer 21 of the donor substrate 12. FIG.

[0138] In principle, the doping of the first layer 21 is such that the doping concentration (conc) in the first layer 21 is 1E15 cm -3 ~5E17cm -3 The doping is p-doped or n-doped.

[0139] FIG. 7 a shows the result of an optional step of creating a contact layer 24 in a surface region of the first layer 21 or applying a contact layer 24 to the surface of the first layer 21 .

[0140] The contact layer 24 is preferably created by ion implantation into the first layer 24. Here, the contact layer 24 has a thickness of only 10 nm to 1 μm. Preferably, P, N or Al ions are used for implantation (without energy filtering).

[0141] The dopant concentration of the contact layer 24 is preferably at least 100 times, more preferably at least 1000 times, more preferably at least 10,000 times, and even more preferably at least 100,000 times higher than the remainder of the first layer 21 or the average dopant concentration of the first layer 21.

[0142] The dopant concentration of the contact layer 24 is 1E17 cm -3 Larger is preferable, 1E19cm -3 Larger is more preferable.

[0143] It is also possible to apply a thin contact layer 24, for example a few nanometers thick, to the first layer 21. This is carried out, for example, by sputter deposition, evaporation or CVD deposition. The contact layer 24 does not have to be completely covered and can also consist of nanoparticles.

[0144] Simultaneously with or after the layer application of the contact layer 24, further treatment of the surface, for example physical back-etching, can be performed.

[0145] As shown in Fig. 7b, after the ion implantation into the donor substrate 12 and possibly after the manufacture of the contact layer has been completed, there is a first possibility to carry out a repair step according to the invention by laser irradiation 43. This is indicated only diagrammatically by the arrow 43 in the figure. In practice, the laser irradiation 43 is carried out at many different points of the donor substrate 12. Details of the repair step are explained further below with reference to Fig. 13.

[0146] In a next step, according to Fig. 8, a predetermined damage site 26 is created in the donor substrate 24. The predetermined damage site 26 in the example of Fig. 8 is in a region of the first layer 21, preferably in an edge region of the first layer 21 close to the predetermined doping depth T. Here, the predetermined damage site 26 is preferably at a distance of 1 μm or less, more preferably 500 nm or less, particularly preferably 100 nm or less from the doping depth T and thus from the edge of the first layer 21. In particular, for a rectangular contour with descending sides, the predetermined damage site 26 should still be in the region of the plateau.

[0147] The creation of the predetermined damage site 26 is preferably carried out by ion implantation of split trigger ions, which are shown diagrammatically as black dots in FIG. 8. No energy filters are used here. According to FIG. 8, the split trigger ions are introduced over the entire width of the donor substrate 12. The split trigger ions are preferably selected from H, H2, He, B. The split trigger ions have an energy between 0.5 and 10 MeV, preferably between 0.5 and 5 MeV, more preferably between 0.5 and 2 MeV. For hydrogen, with an ion energy of 0.6 MeV the formation of the predetermined damage site 26 will be about 5 μm deep, with an ion energy of 1.0 MeV it will be about 10 μm deep and with an ion energy of 1.5 MeV it will be about 20 μm deep.

[0148] The particle dose of the split trigger ion is 1E15 cm in each case. -2 and 5E17cm -2 The energy sharpness (ΔE / E) of the ion beam of the split trigger ion is preferably between 10 -2 Less than 10, more preferably -4 During implantation of the split trigger ions, it is advantageous if the temperature within the donor substrate 12 is maintained below 300° C., preferably below 200° C. To this end, the chuck on which the donor substrate 12 rests may be cooled if necessary.

[0149] Using these parameters, a doping profile with a sharp peak is created (see Gaussian distribution shown in FIG. 3A). In this way, it is possible to ensure that the predefined damage sites 26 have a high concentration of doping distributed over a very small thickness. The variation in the range of the ions in the donor substrate 12 (longitudinal scattering σ) is only between 100 nm and 500 nm, preferably between 200 nm and 400 nm, depending on the primary energy of the ion beam.

[0150] 9 based on the arrows and the black horizontal bars, the split trigger ions can be introduced only in a portion of the width of the donor substrate 12, preferably only in one or both edge regions of the donor substrate 12. In this way, the predetermined damage site 26 is predefined in several sections.

[0151] In addition to ion implantation, the predetermined damaged portion 26 can also be formed by electron irradiation or laser irradiation.

[0152] At this point, a repair step of the implantation defects can be carried out for the first time or again, preferably by laser irradiation, as shown in FIG. 7b.

[0153] The donor substrate 12 is then bonded side-on with the first layer 21 by a bonding connection to the acceptor substrate 28, as shown diagrammatically in Figure 10. The first layer 21 is thus disposed in the region between the acceptor substrate 28 and the remaining portion 22 of the donor substrate 12. It is irrelevant whether the donor substrate 12 is moved towards the acceptor substrate 28 to create the bonding connection, as indicated by the curved arrow in Figure 10, which also indicates whether the donor substrate 12 is flipped over or the acceptor substrate 28 is moved towards the donor substrate 12.

[0154] An intermediate result of the bonding process is shown in the bottom left of Figure 10. If the acceptor substrate 28 is moved towards the donor substrate 12, the order of the layers can also be reversed, for example:

[0155] Although the contact layer 24 is not shown in either case in Figures 9 and 10, it is preferably present. In this case, the creation of a bonded connection between the donor substrate 12 and the acceptor substrate 28 takes place via the contact layer 24, resulting in the following sequence: acceptor substrate 28, contact layer 24, remaining part of the first layer 21 or first layer 21, remaining part 22 of the donor substrate 12.

[0156] The creation of low resistance bonding connections is preferably carried out by temperature treating the intermediate resulting substrate at a temperature between 800°C and 1400°C, more preferably between 900°C and 1300°C.

[0157] Prior to the step of creating the bonded connection, at least one, but preferably both, surfaces to be bonded can be pretreated, in particular by wet-chemical, plasma or ion beam treatment. One treated surface can be a contact layer 24. It is also conceivable to apply a thin layer with a thickness of a few nanometers in order to create a subsequent low-resistance connection between the acceptor substrate 28 and the donor substrate 12. In principle, a very low resistance contact between the acceptor substrate 28 and the donor substrate 12 is important.

[0158] In principle, a permanent bonded connection between the acceptor substrate 28 and the donor substrate 12 is preferred, which also remains present in the resulting semiconductor component. However, a temporary bonded connection or fixation between the acceptor substrate 28 and the donor substrate 12, for example for some process steps, is also conceivable. This opens up the possibility to carry out further process steps, such as, for example, ion implantation and possibly subsequent repair steps, after removing and exposing the acceptor substrate from a side.

[0159] 11 illustrates diagrammatically the step of splitting the donor substrate 12 in the region of the predetermined breakage site 26, thereby creating a preprocessed composite substrate 18 including an acceptor substrate 28 and a doped layer 32 connected thereto, where the doped layer 32 constitutes at least a portion of the first layer 21 of the donor substrate 12. The portion 34 of the donor substrate 12 that has been separated from the acceptor substrate 28 is removed.

[0160] Splitting of the donor substrate 12 is preferably induced by temperature treatment of the composite substrate 18 at a temperature between 600° C. and 1300° C., preferably between 750° C. and 1200° C., more preferably between 850° C. and 1050° C. In one embodiment shown in Figures 8 and 9, the implanted ions form bubbles which grow together and cause the splitting.

[0161] Alternatively, an external force can be applied to the composite substrate 18 to break the donor substrate 12 along the predetermined break site 26. A combination of heat treatment and an external force may also be necessary or useful, especially when ions are introduced into only some portions of the donor substrate 12. The application of an external force is unavoidable.

[0162] When both creating the bonded connections and splitting the donor substrate 12 are performed by temperature treatments, both steps can be performed simultaneously under certain circumstances.

[0163] Furthermore, as diagrammatically indicated by the arrows in Figure 12, after the splitting step, a post-treatment of the first surface of the composite substrate 18 can be carried out, in particular by polishing and / or defect removal and / or grinding, in the area of ​​the predetermined breakage sites 26. Chemical-mechanical polishing is the preferred method.

[0164] The implantation defect 42 shown diagrammatically in FIG. 13 a may ultimately be repaired within the doped layer 32 of the pre-processed composite substrate 18 .

[0165] The repair step is preferably performed by laser irradiation 43 and is shown diagrammatically in Fig. 13b. The desired temperature distribution is preferably achieved by suitable selection of the irradiation points or areas and the parameters of the laser beam. In this way, defects in the near-surface areas can be repaired while maintaining lower temperatures in deeper layers of the substrate. Three irradiation points are shown as an example in Fig. 13b, with isothermal lines shown diagrammatically (e.g. dotted line at 1650°C, dashed line at 1500°C). The desired temperature gradient is realized by superimposing various temperature introductions.

[0166] The composite substrate 18 used as a basis for further processing to form electronic semiconductor components is again shown in Figure 13a. It includes an acceptor substrate 28 and a doped layer 32 of single crystal SiC bonded thereto. In addition, a contact layer 24 may be included between the acceptor substrate 28 and the doped layer 32.

[0167] The doped layer 32 preferably has a thickness between 3 μm and 30 μm, more preferably between 3 μm and 15 μm. It is preferably made of SiC of 4H, 6H or 3C polytype. The doped layer 32 preferably has p-doping or n-doping with a doping concentration between 1E15 cm-3 and 5E17 cm-3. The doped layer 32 is preferably doped with ions of one of the elements N, P, B or Al as dopant.

[0168] The dopant depth profile of doped layer 32 preferably results from substantially the inverse of the dopant depth profile of first layer 21 of donor substrate 12 .

[0169] Thus, doped layer 32 may, for example, have a substantially constant dopant depth profile.

[0170] The doped layer 32 may also have a dopant depth profile that rises stepwise toward the acceptor substrate 28, with the step in the region of the doped layer 32 facing the acceptor substrate 28 being up to 40%, preferably 30%, of the total depth of the doped layer 32.

[0171] The doped layer 32 may also provide a dopant depth profile that rises continuously toward the acceptor substrate 28 .

[0172] The implant defect profile substantially follows the depth profile of the implanted foreign atom concentration.

[0173] 14 shows another embodiment of a pretreated composite substrate 18 in cross-section, below which is shown the dopant concentration profile along the cross-section of the composite substrate 18 according to arrow F. This is particularly suitable for the fabrication of very high blocking components, e.g., above 600V.

[0174] In this case, the preprocessed composite substrate 18 has, in addition to the doped layer 32, an auxiliary doped layer 38 made of single crystal SiC. The overlap region 40 of the respective dopant depth profiles preferably exists at the transition section between the doped layer 32 and the auxiliary doped layer 38.

[0175] In the embodiment shown in FIG. 13a, the necessary active layers (drift zone, voltage absorption layer) of the subsequent semiconductor component are formed only by the doped layer 32 and therefore simultaneously by the first layer 21 or a (preferably large) part of the first layer 21 of the donor substrate 12.

[0176] In contrast, the active layer is formed by a combination of the doped layer 32 and the auxiliary doped layer 38 in an embodiment such as that of Fig. 14. Although in Fig. 14 a substantially constant total doping profile is obtained by the superposition of two partial profiles, any other doping profile can also be formed by the concatenation and partial overlap of the doping profiles in the doped layer 32 and the auxiliary doped layer 38. The combined overall doping profile, consisting of the combination of the dopant depth profiles of both the doped layer 32 and the auxiliary doped layer 38, may thus be a stepwise rising profile towards the acceptor substrate 28 or a continuous rising profile towards the acceptor substrate 28.

[0177] A more particularly preferred doping profile is described in more detail below with reference to FIG.

[0178] In each of these embodiments, reference number 48 denotes a first section of the donor substrate 12, which in each case remains part of the composite substrate 18 after splitting. This first section 48 can consist of only the doped layer 32, in the absence of the auxiliary doped layer 38 (Figure 13a), or it can consist of a combination of the doped layer 32 and the auxiliary doped layer 38 (Figures 14, 20).

[0179] Such a composite profile is obtained in that the predetermined damage site 26 in the donor substrate 12 is not created in the first layer 21, but rather is generated in the remaining portion 22 of the donor substrate 12 that was not doped by ion implantation into the donor substrate 12.

[0180] After splitting at the predetermined break site 26 as in FIG. 11, doping of the auxiliary doped layer 38 can be carried out from the side opposite the acceptor substrate 28 by further ion implantation with energy filters. The above description of FIGS. 2-6 regarding ion implantation with energy filters applies equally to the ion implantation into the auxiliary doped layer 38. The thickness of the auxiliary doped layer 38 is generally between 3 and 15 μm. In this way, a total thickness of the active zone doped by ion implantation of up to 30 μm is obtained.

[0181] Following the implantation, a repair step according to the invention is performed by laser irradiation 43 to remove the defects in the auxiliary doped layer 38 .

[0182] In principle, more than one composite substrate 18, or even a large number of composite substrates 18, can be produced from one donor substrate 12 using the method according to the invention, provided that the thickness of the donor substrate 12 in FIG. 1 is at least twice the thickness of the required doped layer 32 of the composite substrate 18. This effect is particularly high when using thick wafer rods as donor substrates 12. In this way, significant savings in production costs can be achieved. This is shown diagrammatically in FIG. 15.

[0183] As shown in FIG. 16 , during ion implantation into the first layer 21 of the donor substrate 12 (and / or the auxiliary doped layer 38 of the composite substrate 18) by the energy filter 20, a mask 46 can be used to create one or more undoped regions 44 within the first layer 21 of the donor substrate 12 (and / or within the auxiliary doped layer 38 of the composite substrate 18).

[0184] The composite substrate 18 may be turned into a completed semiconductor component 50 through further steps, such as implanting further active areas, growing oxides, depositing gate electrodes, contacts, lines or vias, etc.

[0185] After the processing of the component, a repair step according to the invention can be performed again or for the first time by laser irradiation 43. For example, defects in source-drain contact implants, channel implants, p-JFET implants, etc. can be removed in the process. This repair can possibly be performed simultaneously with the repair of defects in the auxiliary doped layer 38 or in the doped layer 32 if no auxiliary doped layer is present.

[0186] Two basic base structures for electronic semiconductor components 50 fabricated using this method are shown in FIGS.

[0187] 17 comprises a carrier substrate 52 which typically corresponds to the acceptor substrate 28 of the preprocessed composite substrate 18. The carrier substrate 52 typically comprises a highly doped material and is generally field free.

[0188] A crystal 53 of SiC is applied to the carrier substrate 52. This crystal 53 generally corresponds to the first section 48 of the donor substrate 12 of the preprocessed composite substrate 18.

[0189] The electronic semiconductor component 50 comprises an active component region 64 having a first zone 54 in the area of ​​a first surface 58 and a second zone 56 adjacent the first zone 54 in the depth direction.

[0190] The first zone 54 includes a surface-proximal shield structure 60 or JFET structure in a region that includes at least a subsection of the first surface 58 of the crystal 53. The shield structure or J-FET structure is p + / n transitions are interrupted in one direction. +The regions are formed in several regions (not contiguous) and generally cannot be cleared. The regions with p+ doping are identified by reference numeral 68.

[0191] The second zone 56 comprises or consists of a voltage absorbing layer (also called a drift zone or active layer). The transition between the first zone 54 and the second zone 56 is identified by a dashed line. The thickness of the second zone 56 is preferably between 2 μm and 50 μm.

[0192] 19, the semiconductor component 50 further comprises a field free contact zone or field stop zone 62 at the transition between the second zone 56 and the carrier substrate 52. This field stop zone 62 typically corresponds to the contact layer 24 of the preprocessed composite substrate 18. The field free contact zone or field stop zone 62 has a vertical thickness of up to 2 μm, preferably up to 1 μm.

[0193] The inactive edge region 66 substantially completely surrounds the first zone 54 and the second zone 56 laterally.

[0194] The second basic structure of the semiconductor component 50 shown in FIG. 18 corresponds essentially to the basic structure of FIG. 17. The same reference numerals denote the same elements. The difference is that + Region 60 is not a trench region, but is formed continuously down to first surface 58 .

[0195] All p-doped shield structures 60, regardless of the respective type of semiconductor component 50, have several common features. The shield structures 60 are not formed continuously, but rather periodically interrupted parallel to the first surface 58. The distance is formed for the following reasons: to the first surface 58, to ensure that the maximum allowable electric field strength at the first surface 58 is not exceeded in blocking operation in the "open" area. The shield structures 60 are connected to the source potential, gate potential or anode potential directly or via a line (third dimension, not shown). The shield structures 60 are either embedded in the n-area and placed isolated (except for electrical connections) or formed as doped areas with a high aspect ratio starting from the first surface 58. The typical depth of the pn transition is between 500 nm and 3.0 μm. The shield structures 60 are so heavily doped that even for maximum blocking voltages the area is not cleared.

[0196] The spatial boundary between the first zone 54 and the second zone 56, indicated by the dashed line in Figures 17 and 18, is typically at the point where the p-doped region 68 ends in the depth direction of the crystal 53. The transition is typically defined herein as being parallel to the first surface 58.

[0197] 19 shows only the details of the semiconductor component 50. The right side of each can be seen as a cutaway side.

[0198] 19 shows a vertical power semiconductor component 50 in the form of a planar MOS transistor. The inactive edge region 66 is preferably nominally undoped, except for a possibly present surface-proximal edge structure 70. Reference numeral 52 again denotes the carrier substrate, reference numeral 53 again denotes the SiC crystal, reference numeral 54 again denotes the first zone, reference numeral 56 again denotes the second zone, reference numeral 62 again denotes the field stop zone, reference numeral 68 again denotes the p of the shielding structure. +5 shows a region. Metal contacts 71 are applied to the underside of the carrier substrate 52. G indicates a gate electrode, S indicates a source electrode and D indicates a drain electrode. Reference 72 indicates a p-region (p-well) and reference 74 indicates an n+ region. Reference 75 indicates a further p+ region. The first surface 58 of the crystal 53 is here formed planar and preferably extends over the entire width of the semiconductor component 50. The gate oxide is obviously not considered to be part of the first surface 58.

[0199] There are many more forms of semiconductor components which can be manufactured using the method according to the invention.

[0200] The doping profile (conc) shown in Fig. 20 of the semiconductor component 50 of Fig. 19 has a continuously rising profile in the depth direction in the region of the second zone 56, as already explained for the pretreated composite substrate 18. Alternatively, the doping profile can be consistent in the region of the second zone 56 or can be a stepped rising profile in the end region of the second zone 56, as indicated by the dashed line. How such a doping profile is obtained has already been explained in detail with reference to Figs. 6a to 6c.

[0201] Furthermore, it is preferred that in the region of the first zone 54 the doping profile has a higher plateau than the doping in the region of the second zone 56 adjacent thereto. In general, the regions of the first zone 54 and the second zone 56 are each n-doped. The doping concentration of the n-doped region of the first zone 54 is preferably 1.5 to 100 times higher, in particular 2 to 10 times higher, than the n-doped region of the second zone 56 facing the first zone 54. The descending flanks of the doping profile are usually not perfectly vertical.

[0202] Of course, doping deviating from the profile shown may be obtained in the p+ region 68 of the first zone 54. +The doping concentration in the region 68 is preferably 2 to 1000 times higher, particularly preferably 50 to 1000 times higher, than the doping concentration of the n-doped region of the second zone 56 facing the first zone 54 .

[0203] Contrary to Fig. 20, it is also possible for the doping profiles of the first zone 54 and the second zone 56 to be substantially coplanar and adjacent to each other. This is obvious if the first zone 54 and the second zone 56 are doped by the same implantation process (similar to the doped layer 32 of the donor substrate 12). However, this is also possible if the first zone 54 is doped first in a downstream implantation process (e.g. as the auxiliary doped layer 38).

[0204] The doping profile of the second zone 56 of FIG. 20 is essentially applicable to many other semiconductor components 50 .

[0205] Within the scope of the present invention, "connected" is to be understood as being connected directly or indirectly, i.e. via an intervening further element. A "connection" between two elements may be direct or indirect.

Claims

1. A method for manufacturing an electronic semiconductor component (50) via an intermediate step of creating a pre-treated composite substrate (18), wherein the pre-treated composite substrate (18) includes an acceptor substrate (28) and a first section (48) of a donor substrate (12), and the first section (48) has at least one doped layer (32). a) Providing a donor substrate (12) containing single crystal SiC; b) Doping a first layer (21) of the donor substrate (12) by ion implantation, wherein a predetermined dopant depth profile is created in the first layer (21) of the donor substrate (12) during doping, where the first layer (21) extends from an outer surface (23) of the donor substrate (12) facing the ion beam (10) to a predetermined doping depth (T), and where the remaining portion (22) of the donor substrate (12) is adjacent; c) Creating a predetermined fracture site (26) within the donor substrate (12) that extends substantially parallel to the outer surface (23) of the donor substrate (12); d) Providing the acceptor substrate (28) and generating a connection between the donor substrate (12) and the acceptor substrate (28), wherein the first layer (21) is disposed in a region between the acceptor substrate (28) and the remaining portion (22) of the donor substrate (12); e) Dividing the donor substrate (12) in the region of the predetermined fracture site (26) to create the pre-treated composite substrate (18), wherein the pre-treated composite substrate (18) includes the acceptor substrate (28) and a first section (48) of the donor substrate (12) connected thereto, the first section (48) has at least one doped layer (32), the doped layer (32) constitutes at least one section of the first layer (21) of the donor substrate (12), and the pre-treated composite substrate (18) has a first surface (58) in the region of the predetermined fracture site (26) after division; f) Introducing at least one further structural element of the semiconductor component (50) into the composite substrate (18) from the first surface (58) and / or disposing at least one further structural element of the semiconductor component (50) on the first surface (58). A method comprising: A method in which, after at least one of steps b), c), e) and / or after or during step f), a repair step of implantation defects is carried out in the first layer (21) of the donor substrate (12) and / or in the first section (48) of the donor substrate (12) by laser irradiation (43).

2. The method according to claim 1, wherein the repair step by laser irradiation (43) is carried out after step e) and / or after or during step f).

3. The method according to claim 2, wherein after step e) and / or after or during step f), the repair step is carried out by laser irradiation (43) on the first surface (58) of the composite substrate (18).

4. The method according to claim 2, wherein during the repair step by laser irradiation (43) after step e) and / or after or during step f), the temperature of the region of the acceptor substrate (28) does not exceed 1400 °C.

5. The method according to claim 2, wherein during the repair step by laser irradiation (43) after step e) and / or after or during step f), a temperature gradient is formed in the composite substrate (18), and the temperature is higher near the first surface (58) than in the acceptor substrate (28).

6. The method according to claim 5, wherein the temperature in the doped layer (32) during the repair step by laser irradiation (43) after step e) and / or after or during step f) is at least 1450 °C.

7. The predetermined damaged site (26) is in the region of the remaining part (22) of the donor substrate (12), and further, after step e) and before the repair step, preferably using an energy filter (20), an ion implantation step is carried out on the composite substrate (18) from the first surface (58), thereby forming an auxiliary doped layer (38). The method according to claim 5.

8. The method according to claim 7, wherein the ion implantation into the composite substrate (18) reaches at least the doped layer (32).

9. The ion implantation into the composite substrate (18) is carried out such that the doping concentration of the auxiliary doped layer (38) is higher than the doping concentration of the region of the doped layer (32) facing the auxiliary doped layer (38), according to the method of claim 8.

10. After step e), and / or after step f) or during that step, the temperature in the auxiliary doped layer (38) during the repair step by the laser irradiation (43) is at least temporarily at least 1450 °C, according to the method of claim 7.

11. The repair step by laser irradiation (43) is carried out after at least one of steps b) and c), according to the method of claim 1.

12. After at least one of steps b) and c), the repair step by laser irradiation (43) is carried out on the outer surface (23) of the donor substrate (12), according to the method of claim 11.

13. During the repair step by laser irradiation (43) after at least one of steps b) and c), the temperature of the region of the remaining part (22) of the donor substrate (12) does not exceed 1450 °C, according to the method of claim 11.

14. During the repair step by laser irradiation (43) after at least one of steps b) and c), a temperature gradient is formed in the donor substrate (12), and the temperature of the first layer (21) is higher than the temperature of the remaining part (22) of the donor substrate (12), according to the method of claim 11.

15. During the repair step by laser irradiation (43) after at least one of steps b) and c), the temperature of the first layer (21) is at least temporarily at least 1450 °C, according to the method of claim 14.

16. The repair step is carried out by introducing light pulses, according to the method of claim 1.

17. For each irradiation point, a number of individual pulses between 100 and 5000 are deposited, according to the method of claim 16.

18. During the repair step, the temperature introduction into the depth and / or the temperature gradient is controlled by the successive or simultaneous application of light of different wavelengths, pulse durations, and / or number of pulses, according to the method of claim 16.

19. The pulse frequency is in the range of 20 Hz to 3 kHz, according to the method of claim 16.

20. The method according to claim 16, wherein the pulse width is in the range of 1 to 1000 ns.

21. The method according to claim 16, wherein the wavelength of the light is in the range between 250 and 400 nm.

22. The method according to claim 1, wherein the first layer (21) has a thickness of 3 to 15 μm.

23. The doping of the first layer (21) is such that the doping concentration in the first layer (21) is 1E15 cm －３ to 5E17 cm －３ The method according to claim 1, wherein n-doping is applied which is such that.

24. The method according to claim 1, wherein the doping of the first layer (21) is carried out using ions of one of the elements nitrogen, phosphorus, boron, or aluminum.

25. The method according to claim 1, wherein the acceptor substrate (28) is stable only at temperatures up to a maximum of 1400 °C.

26. The method according to claim 25, wherein the acceptor substrate (28) is formed from silicon.

27. The doping in step b) is carried out using an energy filter (20), and the energy filter (20) is a microstructure film having a predetermined structural profile for setting the depth profile of dopants caused by implantation in the first layer (21) of the donor substrate (12). The method according to claim 1.

28. Providing a pre-treated composite substrate (18), wherein the pre-treated composite substrate (18) has an acceptor substrate (28) and at least one doped layer (32) made of SiC connected to the acceptor substrate (28). Repairing the implantation defects of the doped layer (32) by laser irradiation (43), wherein the temperature of the region of the acceptor substrate (28) does not exceed 1400 °C. A method for manufacturing an electronic semiconductor component (50) including.

29. The doped layer (32) has a first surface (58) opposite to the acceptor substrate (28), and the laser irradiation (43) is performed on the first surface (58). The method according to claim 28.

30. During the repair step by laser irradiation (43), a temperature gradient is formed in the composite substrate (18), and the temperature is higher near the first surface (58) than in the acceptor substrate (28). The method according to claim 29.

31. The temperature in the doped layer (32) during the repair step by laser irradiation (43) is at least temporarily at least 1450 °C. The method according to claim 28.

32. The method according to claim 28, wherein the repair step is carried out by introducing a pulse of light.

33. The method according to claim 32, wherein between 100 and 5000 individual pulses are deposited for each irradiation point.

34. The method according to claim 28, wherein during the repair step, the temperature introduction into the depth and / or the temperature gradient is controlled by the continuous or simultaneous application of light of different wavelengths, pulse durations, and / or number of pulses.

35. The method according to claim 28, wherein the pulse frequency is in the range of 20 Hz to 3 kHz.

36. The method according to claim 28, wherein the pulse width is in the range of 1 to 1000 ns.

37. The method according to claim 28, wherein the wavelength of the light is in the range between 250 and 400 nm.

38. The method according to claim 28, wherein the acceptor substrate (28) is stable only at temperatures up to a maximum of 1400 °C.

39. The method according to claim 38, wherein the acceptor substrate (28) is formed from silicon.

40. After the execution of the repair step, at least one further structural element of the semiconductor component (50) is introduced from the first surface (58) into the composite substrate (18) and / or at least one further structural element of the semiconductor component (50) is arranged on the first surface (58), and the method according to claim 29 is carried out.

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