Surface type repairing method of SiC single crystal substrate after hydrogen ion implantation

Abstract

The embodiment of the invention provides a surface type repairing method for a SiC single-crystal substrate after hydrogen ion implantation, the surface type of the substrate after ion implantation of the SiC single-crystal substrate is repaired by utilizing the characteristic that thermal expansion of a grinding disc changes along with temperature, and due to the fact that after the grinding disc is ground and heated, the heat dissipation speed of the edge of the grinding disc and the heat dissipation speed of the middle of the disc face are different, the surface type of the substrate is repaired. The expansion amplitudes of the edge of the grinding disc and the middle of the disc surface are different, so that the contact area and the extrusion force of the edge and the middle of the grinding disc and the SiC single crystal substrate are different, the temperature rising range in the grinding process is controlled, the deformation protruding degree of the grinding disc is controlled, and the concave surface of the SiC single crystal substrate is extruded into a plane under the combined action of extrusion and grinding liquid; therefore, the purpose of repairing the surface type of the SiC single crystal substrate is achieved.

Description

Technical Field

[0001] The present disclosure relates to the field of semiconductor processing technologies, and in particular, to a method for repairing the surface profile of a SiC single crystal substrate after hydrogen ion implantation. Background Art

[0002] Silicon carbide (SiC) is an important material in the third-generation semiconductors, which has excellent properties such as a wide bandgap, a high breakdown electric field, high thermal conductivity, high thermal stability, and high chemical inertness. In recent years, it has become a consensus in the industry to reduce the cost proportion of 6 / 8-inch SiC single crystal substrates at the device end. How to reduce the cost of SiC single crystal substrates has become the key. SiC single crystal substrates are usually grown by physical vapor transport (PVT). It is difficult to improve the growth rate and yield in a short time. Therefore, improving the utilization rate of SiC materials has become the main direction to reduce costs in the short term. Thus, the SiC smart peeling technology for preparing SiC single crystal thin layers by combining ion implantation and bonding processes has become a hot topic. Specifically, high-quality SiC single crystal thin layer transfer can be achieved through hydrogen ion implantation, peeling, and bonding technologies, which can reuse SiC single crystal substrates, reduce material consumption, and obtain high-quality single crystal thin layers at the same time, significantly improving the performance of SiC-based devices. However, high-quality SiC direct bonding has become the most critical technology for realizing this technology.

[0003] High-quality SiC direct bonding requires strict control of the surface profile (Bow / Warp) of the SiC single crystal substrate. The reasons are as follows: 1) Ensure close contact at the interface and reduce defects: Direct bonding depends on atomic-level contact between the surfaces of two substrates. If the surfaces are uneven, voids with a micron or nanometer scale will be generated during bonding. These defects will significantly reduce the bonding strength and become the carrier scattering centers in the device, affecting the electrical performance and reliability; 2) If there is a surface profile mismatch at the bonding interface, temperature changes during high-temperature treatment or subsequent processes will cause stress concentration at the interface, leading to surface cracks or delamination.

[0004] However, after single-sided hydrogen ion implantation of the SiC single crystal substrate, experiments have shown that the surface profile of the SiC single crystal substrate will change greatly. Taking a 6-inch SiC single crystal substrate as an example, the surface profile changes of the SiC single crystal substrate before and after hydrogen ion implantation are shown in the following table:

[0005] Note: >250 indicates that the Bow / Warp value is too large and exceeds the detection limit (250 μm) of the equipment

[0006] Therefore, it is very important to control the surface profile of the SiC single crystal substrate after hydrogen ion implantation and before bonding. Summary of the Invention

[0007] In view of this, embodiments of the present disclosure provide a method for repairing the surface profile of a SiC single crystal substrate after hydrogen ion implantation, which is used to solve the problem that the surface profile of the SiC single crystal substrate deteriorates after hydrogen ion implantation, control the surface profile of the SiC substrate in place before bonding, and prevent the generation of Voids defects and insufficient bonding force during the bonding process.

[0008] A method for repairing the surface profile of a SiC single crystal substrate after hydrogen ion implantation provided by an embodiment of the present disclosure includes: S1. Perform surface profile detection on multiple SiC single crystal substrates after hydrogen ion implantation to detect the curvature and warpage; S2. Continuously group the SiC single crystal substrates with a curvature greater than or equal to a first preset value according to the span between the maximum and minimum curvature values within a second preset value; S3. Provide a polishing pad with a coefficient of thermal expansion in the range of 15×10 -6 / °C to 24×10 -6 / °C. According to the grouping situation, determine the concavity of the polishing pad corresponding to the curvature of each group of SiC single crystal substrates, perform disc engraving and trimming on the polishing pad, and form an annular groove on the surface of the concave polishing pad; S4. Paste the hydrogen ion implantation surface of the SiC single crystal substrates in the same group on the same ceramic disc, make the non-implantation surface of the SiC single crystal substrates pasted on the ceramic disc contact the polishing pad, fix the polishing head of the single-sided polishing machine and the ceramic disc, and drop a polishing liquid on the surface of the polishing pad to perform polishing on the SiC single crystal substrates; S5. During the polishing process, control the surface temperature of the polishing pad to be 25~45°C to ensure that the polishing pad deforms to repair the surface profile of the SiC single crystal substrate; S6. Remove the SiC single crystal substrate and clean the SiC single crystal substrate; S7. Detect the curvature and warpage of each SiC single crystal substrate, determine whether the curvature is less than the first preset value, and determine whether the warpage is less than a third preset value; if so, the repair is successful; if not, execute steps S4~S7 until the curvature is less than the first preset value and the warpage is less than the third preset value.

[0009] In some embodiments, in the method for repairing the surface profile of a SiC single crystal substrate after hydrogen ion implantation provided by the embodiments of the present disclosure, in step S1, the implantation depth of hydrogen ions is 0.5~3 μm, the implantation dose of hydrogen ions is 1×10 14 ~1×10 17 cm -2 , and the implantation energy of hydrogen ions is 60~400 KeV.

[0010] In some embodiments, in the surface profile repair method of the SiC single crystal substrate after hydrogen ion implantation provided by the embodiments of the present disclosure, in step S2, the first preset value is 30 μm, and the second preset value is 50 ± 5 μm; The SiC single crystal substrates with a curvature greater than or equal to the first preset value are divided into four groups: the first group has a corresponding curvature of [30, 80) μm, the second group has a corresponding curvature of [80, 130) μm, the third group has a corresponding curvature of [130, 180) μm, and the fourth group has a corresponding curvature of [180, 230) μm.

[0011] In some embodiments, in the surface profile repair method of the SiC single crystal substrate after hydrogen ion implantation provided by the embodiments of the present disclosure, in step S3, the concavity of the grinding disc corresponding to the first group is 40 ± 10 μm, the concavity of the grinding disc corresponding to the second group is 65 ± 10 μm, the concavity of the grinding disc corresponding to the third group is 90 ± 10 μm, and the concavity of the grinding disc corresponding to the fourth group is 115 ± 10 μm.

[0012] In some embodiments, in the surface profile repair method of the SiC single crystal substrate after hydrogen ion implantation provided by the embodiments of the present disclosure, in step S3, the center of the grinding disc has an opening penetrating its thickness, the diameter of the grinding disc is 720 - 1080 mm, the thickness of the grinding disc is 5 - 30 mm, the planar shape of the annular groove is spiral or concentric circular with the center point of the grinding disc surface as the center, the cross-sectional shape of the annular groove along the diameter direction of the grinding disc surface is V-shaped or U-shaped, the depth of the annular groove is 0.5 - 0.8 mm, and the spacing of the annular groove is 1 - 10 mm.

[0013] In some embodiments, in the surface profile repair method of the SiC single crystal substrate after hydrogen ion implantation provided by the embodiments of the present disclosure, in step S4, the specific operation of pasting the hydrogen ion implantation surface of the SiC single crystal substrates in the same group on the same ceramic disc includes: Adopting a wax pasting process or an adsorption pad to paste the hydrogen ion implantation surface of the SiC single crystal substrates in the same group on the same ceramic disc.

[0014] In some embodiments, in the surface profile repair method of the SiC single crystal substrate after hydrogen ion implantation provided by the embodiments of the present disclosure, in step S4, the specific operation of fixing the grinding head of the single-sided grinding machine and the ceramic disc includes: Align the grinding head of the single-sided grinding machine with the edge of the ceramic disc, and completely inlay the grinding head and the ceramic disc.

[0015] In some embodiments, in the surface profile repair method of the SiC single crystal substrate after hydrogen ion implantation provided in the embodiments of the present disclosure, in step S4, the parameters of the grinding process include: the grinding pressure is 15 - 30 kg / sheet, the rotation speed of the grinding head driving the ceramic disk is 40 - 60 r / min, the rotation speed of the grinding disk is 20 - 35 r / min, the grinding fluid is a nano-diamond grinding fluid with a particle size of 0.1 - 0.3 μm, the flow rate of the dropped grinding fluid is 0.003 - 0.02 L / min, the thickness of the SiC single crystal substrate ground off is 3 - 10 μm, and the grinding time is 5 - 20 min.

[0016] In some embodiments, in the surface profile repair method of the SiC single crystal substrate after hydrogen ion implantation provided in the embodiments of the present disclosure, the grinding disk is any one of a pure copper disk, a brass disk, an aluminum alloy disk, and a copper-nickel alloy disk.

[0017] In some embodiments, in the surface profile repair method of the SiC single crystal substrate after hydrogen ion implantation provided in the embodiments of the present disclosure, in step S6, the SiC single crystal substrate is removed and the SiC single crystal substrate is cleaned, which specifically includes: The ceramic disk with the SiC single crystal substrate attached is placed on a heating platform, the ceramic disk is heated, after dewaxing, the SiC single crystal substrate is removed, and the SiC single crystal substrate is subjected to organic bath cleaning and RCA cleaning.

[0018] The beneficial effects of the present disclosure are as follows: A surface profile repair method of a SiC single crystal substrate after hydrogen ion implantation provided by an embodiment of the present disclosure repairs the surface profile of the substrate after ion implantation of the SiC single crystal substrate by utilizing the characteristic that the thermal expansion of the grinding disk changes with temperature. Since the heat dissipation speeds of the edge and the middle of the grinding disk are different after the grinding disk is heated, and the expansion amplitudes of the edge and the middle of the grinding disk are different, the contact areas and extrusion forces between the edge and the middle of the grinding disk and the SiC single crystal substrate are different. By controlling the range of temperature rise during the grinding process and controlling the convex degree of the deformation of the grinding disk, the concave surface of the SiC single crystal substrate is extruded into a flat surface under the combined action of extrusion and the grinding fluid, so as to achieve the purpose of repairing the surface profile of the SiC single crystal substrate. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic ultrasonic diagram of Void defects after bonding of a SiC single crystal substrate implanted with hydrogen ions; Figure 2 It is a schematic plan view of a copper disk; Figure 3 It is another schematic plan view of a copper disk; Figure 4Schematic diagram of the concavity h corresponding to the case where the surface of the copper disk is engraved into a concave shape; Figure 5 When the copper disk is heated, the surface of the copper disk changes from Figure 4 the concave shape shown to a convex shape. Specific embodiments

[0020] To make the objectives, technical solutions, and advantages of the embodiments of the present disclosure clearer, the technical solutions of the embodiments of the present disclosure will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present disclosure. It should be noted that in the drawings, for clarity, the thicknesses of layers, films, panels, regions, etc. are enlarged. In the present disclosure, exemplary embodiments are described with reference to cross-sectional views that are schematic diagrams of idealized embodiments. Thus, deviations from the shapes of the figures are to be expected as a result of, for example, manufacturing techniques and / or tolerances. Accordingly, the embodiments described in the present disclosure should not be construed as limited to the specific shapes of the regions shown in the present disclosure, but include deviations in shape resulting from, for example, manufacturing. For example, regions illustrated or described as flat may typically have rough and / or non-linear features; sharp corners illustrated may be rounded, etc. Thus, the regions shown in the figures are schematic in nature, and their dimensions and shapes do not represent the exact shapes of the illustrated regions, do not reflect true proportions, and are intended only to schematically illustrate the content of the present disclosure. Also, the same or similar reference numerals represent the same or similar elements or elements having the same or similar functions throughout. To keep the following description of the embodiments of the present disclosure clear and concise, detailed descriptions of known functions and known components are omitted in the present disclosure.

[0021] Unless otherwise defined, the technical terms or scientific terms used herein shall have the ordinary meanings understood by those of ordinary skill in the art to which the present disclosure pertains. The terms "first", "second", and similar terms used in the specification and claims of the present disclosure do not denote any order, quantity, or importance, but are only used to distinguish different components. The terms "comprising" or "including" and similar terms mean that the elements or items appearing before the term cover the elements or items listed after the term and their equivalents, without excluding other elements or items. The terms "connected" or "coupled" and similar terms are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. The terms "inner", "outer", "upper", "lower", etc. are only used to indicate relative positional relationships, and when the absolute position of the object being described changes, the relative positional relationship may also change accordingly.

[0022] In the following description, when an element or layer is referred to as "on" or "connected to" another element or layer, the element or layer can be directly on the other element or layer, directly connected to the other element or layer, or there may be intermediate elements or intermediate layers. When an element or layer is referred to as "disposed on one side of" another element or layer, the element or layer can be directly on one side of the other element or layer, directly connected to the other element or layer, or there may be intermediate elements or intermediate layers. However, when an element or layer is referred to as "directly on" or "directly connected to" another element or layer, there are no intermediate elements or intermediate layers. The term "and / or" includes any and all combinations of one or more of the related listed items.

[0023] Since the surface profile of the SiC single crystal substrate deteriorates after hydrogen ion implantation, it is unfavorable for the subsequent bonding process and is likely to cause defects such as Voids and splitting at the bonding interface, as Figure 1 shown. Figure 1 Fig. is a schematic ultrasonic diagram of the Void defect after bonding of the SiC single crystal substrate implanted with hydrogen ions. It can be seen that there are defects such as Voids and splitting at the bonding interface (shown by the red dots).

[0024] In view of this, in order to solve the problem of the deteriorated surface profile of the SiC single crystal substrate after hydrogen ion implantation, the embodiments of the present disclosure provide a method for repairing the surface profile of the SiC single crystal substrate after hydrogen ion implantation. The following describes the surface profile repair method in detail with specific embodiments.

[0025] Embodiment 1. The method for repairing the surface profile of the SiC single crystal substrate after hydrogen ion implantation may specifically include the following steps: S1. Use a surface profiler (FRT or Tropel) to perform surface profile detection on multiple 6-inch or 8-inch SiC single crystal substrates after hydrogen ion implantation to detect the bow and warp of each SiC single crystal substrate after hydrogen ion implantation. Among them, the implantation depth of hydrogen ions is 0.5 - 3 μm, the implantation dose of hydrogen ions is 1×10 14 ~1×10 17 cm -2 , and the implantation energy of hydrogen ions is 60 - 400 KeV.

[0026] S2. Continuously group the SiC single crystal substrates with a bow greater than or equal to the first preset value according to the span between the maximum and minimum values of the bow within the second preset value. For example, the first preset value is 30 μm, that is, the surface with a bow less than 30 μm has good flatness and does not need to be repaired; the second preset value can be 50 ± 5 μm, and in this embodiment, the second preset value is taken as 50 μm. For example, the SiC single crystal substrates with a bow greater than or equal to 30 μm are divided into four groups: the first group of SiC single crystal substrates has a bow corresponding to [30, 80) μm, the second group of SiC single crystal substrates has a bow corresponding to [80, 130) μm, the third group of SiC single crystal substrates has a bow corresponding to [130, 180) μm, and the fourth group of SiC single crystal substrates has a bow corresponding to [180, 230) μm. Of course, it is not limited to four groups.

[0027] S3. Provide a polishing disk with a coefficient of thermal expansion in the range of 15×10 -6 / °C to 24×10 -6 / °C, such as any one of a pure copper disk, a brass disk (with a small amount of zinc element doped in the copper disk), an aluminum alloy disk, and a copper-nickel alloy disk. In this embodiment, a pure copper disk (hereinafter referred to as a copper disk) is used, and the purity of the copper disk is above 99.9%. As Figure 2 and Figure 3 shown, Figure 2 is a schematic plan view of a copper disk, Figure 3 is another schematic plan view of the copper disk. The center of the copper disk has an opening through its thickness. The diameter AB of the copper disk is 720 - 1080 mm, and the thickness of the copper disk is 5 - 30 mm. According to the grouping situation in step S2, determine the concavity of the copper disk corresponding to the bow of each group of SiC single crystal substrates, engrave the copper disk, grind the surface of the engraved copper disk with a dressing disk to remove surface burrs, and polish it to a mirror surface to ensure close fit with the SiC single crystal substrate. As Figures 2 - 4 shown, Figure 2 and Figure 3 DE in represents the approximate area for measuring the concavity of the copper disk, Figure 4Schematic diagram of the concavity h corresponding to the case where the surface of the copper disk is engraved into a concave shape. The concavity h is the distance from the center of DE to the horizontal plane (dashed line). For example, for the first group of curvatures in the range of [30, 80) μm, the concavity h of the corresponding copper disk is 40 ± 10 μm, and in this embodiment, the concavity h of the copper disk corresponding to the first group is taken as 40 μm; for the second group of curvatures in the range of [80, 130) μm, the concavity h of the corresponding copper disk is 65 ± 10 μm, and in this embodiment, the concavity h of the copper disk corresponding to the second group is taken as 65 μm; for the third group of curvatures in the range of [130, 180), the concavity h of the corresponding copper disk is 90 ± 10 μm, and in this embodiment, the concavity h of the copper disk corresponding to the third group is taken as 90 μm; for the fourth group of curvatures in the range of [180, 230) μm, the concavity h of the corresponding copper disk is 115 ± 10 μm, and in this embodiment, the concavity h of the copper disk corresponding to the fourth group is taken as 115 μm. Then, a V-shaped diamond cutter is used to groove the surface of the copper disk with the above concavity to form an annular groove. The design of the annular groove is beneficial to the flow of the grinding fluid during subsequent grinding, as Figure 2 shown. The planar shape of the annular groove (shown by the dashed line) is spiral with the center point C of the copper disk surface as the center, as Figure 3 shown. The planar shape of the annular groove (shown by the dashed line) is concentric circular with the center point C of the copper disk surface as the center. The cross-sectional shape of the annular groove along the diameter AB direction of the copper disk surface is V-shaped or U-shaped. In this embodiment, the grooving method of the copper disk adopts the spiral shape as Figure 2 shown, and taking the V-shaped groove as an example of the groove type, the depth of the annular groove is 0.5 - 0.8 mm, and the spacing of the annular grooves can be 1 - 10 mm. Specifically, it can be that each group of SiC single crystal substrates corresponds to a copper disk, and the corresponding concavity for copper disk repair is designed according to the Bow of different groups, while controlling the grooving shape (V-shaped and U-shaped) of the copper disk. It can also be that each group of SiC single crystal substrates corresponds to the same copper disk, and the disk is grooved according to the concavity corresponding to each group.

[0028] S4. As Figure 2As shown, prepare a ceramic plate. Use the wax pasting process to paste the hydrogen ion implantation surfaces of the SiC single crystal substrates in the same group onto the same ceramic plate. After curing, bring the non-implanted surfaces of the SiC single crystal substrates pasted on the ceramic plate into contact with the copper plate, that is, place the side of the ceramic plate with the SiC single crystal substrates pasted on it on the surface of the copper plate. Then fix the grinding head and the ceramic plate of the single-sided grinding machine. For example, align the grinding head of the single-sided grinding machine with the edge of the ceramic plate and fully embed the grinding head and the ceramic plate. Drop nano-diamond grinding fluid with a particle size of 0.1 - 0.3 μm on the surface of the copper plate to grind the SiC single crystal substrates. The grinding pressure is 15 - 30 kg / sheet, the rotation speed of the grinding head driving the ceramic plate is 40 - 60 r / min, the rotation speed of the copper plate is 20 - 35 r / min, the flow rate of the dropped grinding fluid is 0.003 - 0.02 L / min, the thickness of the SiC single crystal substrates ground off is 3 - 10 μm, and the grinding processing time is 5 - 20 min. Determine the specific processing time according to the surface profile of the SiC single crystal substrates.

[0029] Optionally, in the above step S4, an adsorption pad can also be pasted onto the ceramic plate, and then the implantation surfaces of the SiC single crystal substrates are adsorbed onto the adsorption pad to achieve pasting the hydrogen ion implantation surfaces of the SiC single crystal substrates in the same group onto the same ceramic plate.

[0030] S5. Observe the temperature on the surface of the copper plate during the grinding process, and control the temperature of the surface of the copper plate to be 25 - 45 °C. Further, the temperature of the surface of the copper plate can be controlled to be 28 - 36 °C to ensure that the copper plate undergoes appropriate deformation to repair the surface profile of the SiC single crystal substrates. As Figure 5 shown, Figure 5 After the copper plate is heated, the surface of the copper plate changes from the concave shape shown in Figure 4 to the convex shape shown in Figure 5 ; Then when repairing the surface profile of the SiC single crystal substrates, control the temperature of the surface of the copper plate during the processing of the SiC single crystal substrates on the copper plate to control the deformation amount of the copper plate, and under the condition of using nano-diamond grinding fluid as the grinding auxiliary material, achieve the purpose of repairing the surface profiles of different SiC single crystal substrates after hydrogen ion implantation. Specifically, as Figure 2As shown, the ceramic disc rotates and grinds on the copper disc. The ceramic disc moves close to the edge of the copper disc. The hydrogen ion implantation surface of the SiC single crystal substrate is generally convex, and the non-implanted surface (the surface in contact with the copper disc) is concave. The edge regions of the copper disc and the SiC single crystal substrate are in contact. Due to the concave surface, the central region of the SiC single crystal substrate may not be in complete contact with the copper disc. The present disclosure repairs the surface shape of the SiC single crystal substrate after ion implantation by utilizing the characteristic that the coefficient of thermal expansion of the copper disc changes with temperature. After the copper disc is heated during grinding, the heat dissipation speeds of the edge and the middle of the copper disc are different, and the expansion amplitudes of the edge and the middle of the copper disc are different, resulting in different contact areas and extrusion forces between the edge and the middle of the copper disc and the SiC single crystal substrate. By controlling the range of temperature rise during the grinding process and controlling the convexity of the deformation of the copper disc, the concave surface of the SiC single crystal substrate is extruded into a flat surface under the combined action of extrusion and grinding fluid, so as to achieve the purpose of repairing the surface shape of the SiC single crystal substrate.

[0031] S6. Place the ceramic disc with the SiC single crystal substrate attached on a heating platform, heat the ceramic disc, and after dewaxing, remove the SiC single crystal substrate and perform organic bath cleaning and RCA cleaning on the SiC single crystal substrate.

[0032] S7. Detect the bow and warp of each SiC single crystal substrate, determine whether the bow is less than the first preset value (30 μm), and determine whether the warp is less than the third preset value (for example, 30 μm); if so, the repair is successful; if not, perform the above steps S4 to S7 for re-repair until the bow is less than the first preset value (30 μm) and the warp is less than the third preset value (30 μm).

[0033] In summary, the present disclosure uses the deformation of the copper disc during the grinding process and cooperates with the processing of nano-diamond grinding fluid to repair the surface shape of the SiC single crystal substrate after hydrogen ion implantation. It is a precision correction technology based on mechanical stress regulation. The repair method of the present disclosure mainly includes the following two points: (1) Deformation transfer mechanism: Utilize the thermal expansion characteristics of the copper disc, make it elastically deform by applying controllable stress (mechanical force and thermal stress), and then transfer the deformation to the SiC single crystal substrate to compensate for the original surface shape error of the SiC single crystal substrate (such as bow-convexity, warp-warpage, etc.).

[0034] (2) Stress matching: The differences in the elastic modulus and coefficient of thermal expansion between the copper disc and the SiC single crystal substrate material need to be accurately calculated, and then the corresponding relationship between the concavity of the copper disc and the surface shape of the SiC single crystal substrate to be repaired is summarized according to process experience to ensure that the deformation is controllable and no secondary damage is introduced.

[0035] Example 2 is different from Example 1 in that: in this example, the grooving method of the copper disc is asFigure 3 The concentric circular grooving method shown.

[0036] Example 3, which is different from Example 1 in that: in this example, the grooving method of the copper disk adopts the Figure 2 spiral grooving method shown, the groove type is a U-shaped groove, and the spacing of the annular grooves is 2-8 mm.

[0037] Example 4, which is different from Example 1 in that: the pure copper disk is replaced with a brass disk.

[0038] Example 5, which is different from Example 2 in that: the pure copper disk is replaced with a copper-nickel alloy disk.

[0039] Example 6, which is different from Example 3 in that: the pure copper disk is replaced with an aluminum alloy disk.

[0040] Through the above Examples 1-6, the present disclosure realizes the surface repair of the SiC single crystal substrate after hydrogen ion implantation. For example, after hydrogen ion implantation: the Bow of a 6-inch SiC single crystal substrate is repaired from >100 μm, even >250 μm to <30 μm; the Warp of a 6-inch SiC single crystal substrate is repaired from >100 μm, even >250 μm to <40 μm; the Bow of an 8-inch SiC single crystal substrate is repaired from >100 μm, even >250 μm to <40 μm; the Warp of an 8-inch SiC single crystal substrate is repaired from >100 μm, even >250 μm to <50 μm. Finally, the purpose of no defects such as Voids at the interface after the bonding of the SiC single crystal substrate is achieved, and the bonding force >1.0 J / m² is successfully realized for the direct bonding and peeling processes in the SiC intelligent peeling technology, solving the high cost and low yield in traditional substrate manufacturing, and will further promote the development of the silicon carbide single crystal substrate towards larger size, higher performance, and lower cost.

[0041] Although the preferred embodiments of the present disclosure have been described, those skilled in the art can make additional changes and modifications to these embodiments once they know the basic creative concepts. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications falling within the scope of the present disclosure.

[0042] Obviously, those skilled in the art can make various changes and modifications to the present disclosure without departing from the spirit and scope of the present disclosure. Thus, if these modifications and variations of the present disclosure fall within the scope of the claims of the present disclosure and their equivalent technologies, the present disclosure also intends to include these modifications and variations therein.

Claims

1. A method for repairing the surface profile of a SiC single crystal substrate after hydrogen ion implantation, characterized in that, Including: S1. Perform surface profile detection on multiple SiC single crystal substrates after hydrogen ion implantation to detect camber and warp. S2. Continuously group the SiC single crystal substrates with camber greater than or equal to the first preset value according to the span between the maximum and minimum values of camber within the second preset value. S3. Provide a polishing pad with a coefficient of thermal expansion in the range of 15×10 -6 / °C to 24×10 -6 / °C. According to the grouping situation, determine the concavity of the polishing pad corresponding to the curvature of each group of SiC single crystal substrates, so as to perform disk engraving and trimming on the polishing pad, and engrave grooves on the surface of the polishing pad with concavity to form annular grooves; S4. Paste the hydrogen ion implantation surfaces of the SiC single crystal substrates in the same group on the same ceramic disk, make the non-implantation surfaces of the SiC single crystal substrates pasted on the ceramic disk contact the grinding disk, fix the grinding head and the ceramic disk of the single-sided grinding machine, and drop grinding fluid on the surface of the grinding disk to grind the SiC single crystal substrates. S5. During the grinding process, control the surface temperature of the grinding disk to be 25 - 45 °C to ensure that the grinding disk deforms to repair the surface profile of the SiC single crystal substrate. S6. Remove the SiC single crystal substrate and clean the SiC single crystal substrate. S7. Detect the camber and warp of each SiC single crystal substrate, determine whether the camber is less than the first preset value, and determine whether the warp is less than the third preset value. If so, the repair is successful; if not, execute steps S4 - S7 until the camber is less than the first preset value and the warp is less than the third preset value.

2. The surface repair method of the SiC single crystal substrate after hydrogen ion implantation according to claim 1, characterized in that, In step S1, the implantation depth of hydrogen ions is 0.5 - 3 μm, the implantation dose of hydrogen ions is 1×10 14 ~1×10 17 cm -2 , and the implantation energy of hydrogen ions is 60 - 400 KeV.

3. The surface repair method of the SiC single crystal substrate after hydrogen ion implantation according to claim 1, characterized in that In step S2, the first preset value is 30 μm, and the second preset value is 50 ± 5 μm. The SiC single crystal substrates with camber greater than or equal to the first preset value are divided into four groups: the first group corresponds to a camber of [30, 80) μm, the second group corresponds to a camber of [80, 130) μm, the third group corresponds to a camber of [130, 180) μm, and the fourth group corresponds to a camber of [180, 230) μm.

4. The method for surface profile repair of the SiC single crystal substrate after hydrogen ion implantation according to claim 3, characterized in that, In step S3, the concavity of the grinding disk corresponding to the first group is 40 ± 10 μm, the concavity of the grinding disk corresponding to the second group is 65 ± 10 μm, the concavity of the grinding disk corresponding to the third group is 90 ± 10 μm, and the concavity of the grinding disk corresponding to the fourth group is 115 ± 10 μm.

5. The surface repair method of the SiC single crystal substrate after hydrogen ion implantation according to claim 1, wherein In step S3, the center of the grinding disk has an opening penetrating its thickness, the diameter of the grinding disk is 720 - 1080 mm, the thickness of the grinding disk is 5 - 30 mm, the planar shape of the annular groove is spiral or concentric circular with the center point of the grinding disk surface as the center, the cross-sectional shape of the annular groove along the diameter direction of the grinding disk surface is V-shaped or U-shaped, the depth of the annular groove is 0.5 - 0.8 mm, and the spacing of the annular groove is 1 - 10 mm.

6. The surface repair method of the SiC single crystal substrate after hydrogen ion implantation according to claim 1, characterized in that, In step S4, the specific method of pasting the hydrogen ion implantation surfaces of the SiC single crystal substrates in the same group on the same ceramic disk includes: Using a wax pasting process or an adsorption pad to paste the hydrogen ion implantation surfaces of the SiC single crystal substrates in the same group on the same ceramic disk.

7. The surface repair method of the SiC single crystal substrate after hydrogen ion implantation according to claim 1, characterized in that, In step S4, the specific method of fixing the grinding head and the ceramic disk of the single-sided grinding machine includes: Align the grinding head of the single-sided grinding machine with the edge of the ceramic disk and completely inlay the grinding head and the ceramic disk.

8. The surface repair method of the SiC single crystal substrate after hydrogen ion implantation according to claim 1, characterized in that, In step S4, the parameters of the grinding process include: the grinding pressure is 15 - 30 kg / sheet, the rotation speed of the grinding head driving the ceramic disk is 40 - 60 r / min, the rotation speed of the grinding disk is 20 - 35 r / min, the grinding fluid is a nano-diamond grinding fluid with a particle size of 0.1 - 0.3 μm, the flow rate of the dropped grinding fluid is 0.003 - 0.02 L / min, the thickness of the SiC single crystal substrate ground off is 3 - 10 μm, and the grinding time is 5 - 20 min.

9. The surface repair method of the SiC single crystal substrate after hydrogen ion implantation according to claim 1, characterized in that, The grinding disk is any one of a pure copper disk, a brass disk, an aluminum alloy disk, and a copper-nickel alloy disk.

10. The surface repair method of the SiC single crystal substrate after hydrogen ion implantation according to claim 1, wherein, In step S6, the SiC single crystal substrate is removed and the SiC single crystal substrate is cleaned, specifically including: The ceramic disk with the SiC single crystal substrate attached is placed on a heating platform, the ceramic disk is heated, after dewaxing, the SiC single crystal substrate is removed, and the SiC single crystal substrate is subjected to organic tank cleaning and RCA cleaning.

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