Substrate placement mechanism, tray assembly, silicon carbide epitaxial device

Abstract

This application discloses a substrate mounting mechanism, a tray assembly, and a silicon carbide epitaxial growth apparatus. The substrate mounting mechanism includes a substrate outer ring, a substrate inner ring, and a substrate fixing part, the substrate inner ring having a hollow region in the center, a positioning part on the inner side of the substrate inner ring, and transition parts on both sides of the positioning part. The substrate outer ring is sleeved onto the substrate inner ring, the substrate outer ring overlaps the substrate inner ring, the substrate fixing part is located below the substrate inner ring, and the substrate fixing part has a support part, the protrusion on the substrate inner ring side of the support part falls on the hollow region, and the support part has discrete protrusions or sub-protrusions, which are used to support the substrate. This design not only reduces the phenomenon of disks or pieces flying off the substrate during epitaxial growth, but also improves temperature uniformity on the substrate side, ensuring epitaxial quality.

Description

[Technical Field]

[0001] The present application relates to the technical field of chemical vapor deposition apparatus, and more particularly to substrate loading mechanisms, tray assemblies, and silicon carbide epitaxial apparatus. [Background technology]

[0002] During operation of a silicon carbide epitaxial system, substrates are placed on a graphite tray within the reaction chamber and heated. Reactant gases flow over the surface of the substrate, which is heated to the reaction temperature, causing a chemical reaction on the surface to produce a single-crystalline film of a consistent thickness. To ensure uniformity of the temperature and airflow on the substrate side, the graphite tray must be rotated at high speeds (typically above 500 r / min (revolutions per minute)). Under high temperature and high rotation speeds, problems such as scattering of substrate discs or pieces and particle deposition on the substrate are highly likely to occur. Furthermore, concentration uniformity in the epitaxial process is highly sensitive to temperature, so improving the uniformity of the temperature zone on the substrate side is also a critical link in the process.

[0003] Figure 1 shows a cross-sectional view of a substrate mounting mechanism currently used for silicon carbide epitaxial growth. The substrate inner ring 1 is mounted on the substrate outer ring 2. In this structure, the mounting surface 1b of the substrate inner ring warps and deforms due to high temperatures during heating. This deformation causes the substrate inner ring to lift, which in turn raises the bottom surface of the substrate inner ring 1. The substrate 10 inside the substrate inner ring 1 is subjected to centrifugal force during high-speed rotation, moving below the bottom surface 1c of the substrate inner ring 1, resulting in the substrate 10 being discarded or even ejected from the tray. Figure 2 shows a schematic top view of the substrate mounting mechanism. During high-speed rotation, centrifugal force causes the tip 11 of the substrate positioning edge 12 of the substrate 10 to contact the cut edge 1a of the corresponding substrate positioning edge of the substrate inner ring 1. At the same time, the tip 11 of the substrate positioning edge 12 at one end along the 180° circumference of the substrate comes into tangential contact with the substrate inner ring 1.

[0004] During the heating process, the substrate 10 expands due to heat. Taking a 6-inch silicon carbide substrate and a graphite tray as an example, the thermal expansion equation is ΔL = α × ΔT × L, where ΔL is the amount of expansion (mm), α is the average thermal expansion coefficient (mm / mm·K), ΔT is the temperature difference (K), and L is the original length (mm). The expansion of a 6-inch silicon carbide substrate from room temperature 293 K to 1273 K is ΔL = 4.4 × 10-6 × (1273 - 293) × 150 = 0.65 mm. This deformation causes both ends of the substrate 10 (both ends of length L in Figure 2) to abut against the substrate inner ring 1. At this time, stress is concentrated at the tip 11 of the substrate positioning edge. Changes in external conditions (temperature, flow field, pressure, rotation speed, etc.) can easily cause stress release at the tip, posing two risks to process growth. 1) During the reaction process, in addition to deposition on the substrate, a large amount of deposition also occurs on the substrate inner ring 1. Due to stress release at the tip 11, the deposits on the substrate inner ring 1 may collapse, causing particles to fall onto the surface of the substrate 10. During the reaction growth process, the fallen particles become embedded, forming defects and reducing the growth yield. 2) As the temperature in the reaction chamber increases further, the expansion volume increases, and the increased stress causes elastic deformation of the substrate 10. When the balance is lost, the elastic potential energy is released, resulting in flying chips. The substrate 10 may fly out due to high-speed rotation, break, and become scrap, damaging other important components in the reaction chamber. Summary of the Invention [Problem to be solved by the invention]

[0005] In order to overcome the above drawbacks, an object of the present invention is to provide a substrate mounting mechanism, a tray assembly, and a silicon carbide epitaxial apparatus that can reduce scattering of disks or pieces, improve temperature uniformity on the substrate, and ensure the quality of the grown epitaxial film. [Means for solving the problem]

[0006] To achieve the above objectives, the present application adopts the following technical solutions: A substrate mounting mechanism for supporting a substrate in an epitaxial apparatus, comprising: a substrate outer ring, a substrate inner ring, and a substrate fixing portion; A hollow area is provided in the center of the substrate inner ring, a positioning portion is provided inside the substrate inner ring, and transition portions are provided on both sides of the positioning portion, The substrate outer ring is sleeved onto the substrate inner ring, and the substrate outer ring overlaps the substrate inner ring, and a first protrusion extending radially inside the substrate outer ring is provided, and the axial thickness of the first protrusion is smaller than the axial thickness of the substrate outer ring; a second protruding portion extending radially outward from the substrate inner ring, an axial thickness of the second protruding portion being smaller than the axial thickness of the substrate outer ring, the first protruding portion abutting the second protruding portion, and the first protruding portion being located above the second protruding portion; The substrate fixing portion is located below the substrate inner ring, and a support portion is provided on the substrate fixing portion, the orthogonal projection of the support portion onto the substrate inner ring being projected onto the cavity region, and the support portion has discrete protrusions or sub-protrusions for supporting the substrate. The epitaxial apparatus may be a silicon carbide epitaxial apparatus. By adopting such a design, the substrate outer ring is sleeved onto the substrate inner ring, preventing the substrate outer ring from being affected by thermal expansion during epitaxial growth, thereby reducing / avoiding the occurrence of substrate disks / pieces popping out during epitaxial growth. With this structure, the weight of the substrate outer ring can be used to press the substrate inner ring, reducing warping of the substrate inner ring and reducing / avoiding the occurrence of substrate disks / pieces popping out during epitaxial growth. By optimizing the support structure, the contact area with the substrate during epitaxial growth is reduced, the temperature change at the contact point is reduced, the temperature on the substrate side is made uniform (the temperature difference between the center and edge of the substrate is within 2°), the radiant heat is made more uniform, and the quality of the grown epitaxial is ensured. The protrusions or sub-protrusions can be individually designed.

[0007] A substrate mounting mechanism for supporting a substrate in an epitaxial apparatus, comprising: a substrate outer ring, a substrate inner ring, and a substrate fixing portion; A hollow area is provided in the center of the substrate inner ring, a positioning portion is provided inside the substrate inner ring, and transition portions are provided on both sides of the positioning portion, The substrate outer ring is sleeved onto the substrate inner ring, and the substrate outer ring overlaps the substrate inner ring, and a first protrusion extending radially inside the substrate outer ring is provided, and the axial thickness of the first protrusion is smaller than the axial thickness of the substrate outer ring; a second protruding portion extending radially outward from the substrate inner ring, an axial thickness of the second protruding portion being smaller than the axial thickness of the substrate outer ring, the first protruding portion abutting the second protruding portion, and the first protruding portion being located above the second protruding portion; The substrate fixing portion is located below the substrate inner ring, and a support portion is provided on the substrate fixing portion, the orthogonal projection of the support portion onto the substrate inner ring is projected onto the hollow area, and the support portion has discrete protrusions or sub-protrusions for supporting the substrate. Preferably, the substrate outer ring is sleeved onto the substrate inner ring, and the substrate outer ring overlaps the substrate inner ring (the substrate inner ring can be pressed by its own weight), and further, a first protrusion is provided on the inner side of the substrate outer ring extending along its radial direction, the axial thickness of the first protrusion is smaller than the axial thickness of the substrate outer ring, and a second protrusion is provided on the outer side of the substrate inner ring extending along its radial direction, the axial thickness of the second protrusion is smaller than the axial thickness of the substrate outer ring, the first protrusion abuts the second protrusion, and the first protrusion is located above the second protrusion (the first protrusion presses the second protrusion and presses the substrate inner ring to reduce the occurrence of disc / piece popping out). This design allows the weight of the substrate outer ring to be used to press the substrate outer ring, reducing or preventing the scattering of disks or pieces of the substrate during epitaxial growth. Furthermore, optimizing the support structure reduces the contact area between the substrate and the substrate during epitaxial growth, reducing temperature changes at the contact points, improving temperature uniformity on the substrate side (the temperature difference between the center and edge of the substrate is within 2°), and making radiant heat more uniform, ensuring the quality of the grown epitaxial layer. The protrusions or sub-protrusions may be individually designed. The epitaxial device may be a silicon carbide epitaxial device. The substrate outer ring and the substrate inner ring may be made of a graphite material, or a protective film (e.g., a silicon carbide film) may be coated on the graphite material. The combined thickness of the first protrusion and the second protrusion is the same as or substantially the same as the axial thickness of the substrate outer ring or the axial thickness of the substrate outer ring.

[0008] In one embodiment, the substrate fixing device further includes a support ring, the support ring being disposed inside the inner ring, and the support portion being disposed on the support ring. By providing the substrate fixing portion, the contact area with the substrate is minimized, and heat conducted to the substrate through the substrate fixing portion during the epitaxial reaction is reduced, thereby suppressing the formation of local temperature spikes.

[0009] In one embodiment, the transition section has rounded corners and / or beveled edges, so that when the substrate thermally expands at high temperatures, the positioning edge of the substrate expands / stretches along the rounded corner tangent or bevel direction of the transition section, and the sharp corner of the substrate is no longer constrained, preventing it from getting caught on the inner ring of the substrate.

[0010] In one embodiment, the plate fixing part includes a boss having a geometric shape such as a cylindrical shape, a truncated cone, a boss formed of discontinuous rings, a rectangular truncated shape, or a trapezoidal truncated shape, etc. By optimizing the structure of the substrate fixing part, the contact area with the substrate is reduced, and heat conducted to the substrate through the substrate fixing part during the epitaxial reaction is reduced, thereby suppressing the formation of local temperature spikes.

[0011] In one embodiment, a first protrusion extending along a radial direction is provided on the inner side of the substrate outer ring, and the axial thickness of the first protrusion is smaller than the axial thickness of the substrate outer ring; a second protruding portion extending radially outward from the substrate inner ring, an axial thickness of the second protruding portion being smaller than the axial thickness of the substrate outer ring, the first protruding portion abutting the second protruding portion, and the first protruding portion being located above the second protruding portion; A receiving cavity is provided between the second protruding portion and the substrate outer ring, and the receiving cavity is for placing a first clamping portion that protrudes along the axial direction on one side of the substrate.

[0012] An embodiment of the present application provides a tray assembly, the tray assembly comprising: The apparatus includes a rotating component, a cover plate is provided on one side of the rotating component, and the substrate placement mechanism is mounted on the cover plate.

[0013] An embodiment of the present application provides a tray assembly, the tray assembly comprising: a rotating component, the rotating component having a cover plate on one side thereof, the cover plate having a main body, the main body having a third protruding rib extending radially at an end thereof, the main body having a fourth protruding rib on a side closer to the third protruding rib, the main body having a fifth protruding rib, a step portion, and a recessed portion on a side of the fourth protruding rib away from the third protruding rib, in that order, the recessed portion being located at the center of the main body, and configured such that when a substrate is placed above the main body, a gap between a surface of the main body and the substrate changes; The substrate placement mechanism is mounted on the cover plate.

[0014] In one embodiment, a flat portion extending radially inward is provided on one side of the rotating component, a second protruding rib extending radially is provided at an end of the flat portion, a notch extending axially is formed in the second protruding rib, and an axial thickness of the second protruding rib is smaller than an axial thickness of the flat portion, The cover plate has a body, and is provided with a third protruding rib extending radially from an end of the body, and at least one protrusion, which is embedded in the notch and abuts the second protruding rib.

[0015] In one embodiment, the flat portion has a first protruding rib extending along the axial direction of the rotating component, the first protruding rib being annular, or a combination of first protruding ribs being annular.

[0016] In one embodiment, a fourth protruding rib is arranged on a side of the main body closer to the third protruding rib, and a step portion is arranged on a side of the fourth protruding rib away from the third protruding rib, and the step portion is configured to change the gap between the surface of the main body and the substrate when a substrate is present above the main body, thereby improving heat conduction from the main body to the substrate.

[0017] An embodiment of the present application provides a silicon carbide epitaxial apparatus, which includes a reaction chamber with a spray element attached to the top, and the tray assembly described above attached to the bottom of the reaction chamber. [Effects of the Invention]

[0018] The advantageous effect of the proposed substrate mounting mechanism and tray assembly is that, through structural optimization, when the substrate outer ring and substrate inner ring are combined, the substrate outer ring can overlap the substrate inner ring, resulting in a flat or inclined overlapping surface. In this way, even if the substrate outer ring deforms due to temperature rise during epitaxial growth, this deformation does not affect the substrate inner ring, preventing the substrate from being inserted under the substrate inner ring and resulting in scattered discs or pieces. The substrate fixing part is provided and its structure is optimized to reduce the contact area with the substrate, minimizing heat transfer to the substrate through the substrate fixing part during the epitaxial reaction, ensuring uniform temperature on the substrate side and ensuring epitaxial quality. The cover body structure is optimized to include a step on the fourth protruding rib side away from the third protruding rib. This creates a gap between the bottom surface of the substrate and the surface of the cover body when the substrate is placed on the cover. This variable gap improves heat transfer to the substrate via body radiation and ensures uniform temperature distribution on the substrate side. By optimizing the structure of the positioning part of the substrate outer ring, transition parts are provided on both sides of it, and the substrate expands due to heat at high temperatures, expanding along the tangential or oblique direction of the fillet of the transition part, preventing the sharp corners of the substrate from being restrained and getting caught on the substrate outer ring, reducing the probability of particles falling on the substrate surface, and improving the yield of epitaxial growth. [Brief explanation of the drawings]

[0019] The accompanying drawings are used to understand the technical solutions of the present invention and constitute a part of this specification. They are used to explain the technical solutions of the present invention together with the embodiments of the present invention, but do not limit the technical solutions of the present invention. The shapes and sizes of the parts in the drawings do not reflect actual proportions and are only intended to explain the contents of the present application. [Figure 1] FIG. 10 is a schematic cross-sectional view of a conventional substrate mounting mechanism. [Figure 2] FIG. 1 is a schematic diagram of a conventional substrate placement mechanism after a substrate is placed thereon. [Figure 3]1 is a schematic diagram of a three-dimensional structure of a tray assembly according to an embodiment of the present invention. [Figure 4] FIG. 4 is a schematic view of the tray assembly of FIG. 3 from a particular viewing angle. [Figure 5] FIG. 5 is a schematic diagram of an isometric cross section taken along line AA in FIG. 4. [Figure 6] FIG. 5 is a schematic cross-sectional view taken along the line AA in FIG. 4. [Figure 7] FIG. 7 is a partially enlarged schematic view of point a in FIG. 6. [Figure 8] FIG. 10 is a schematic cross-sectional view of a substrate mounting mechanism according to another embodiment of the present invention. [Figure 9] FIG. 9 is a partially enlarged schematic view of point c in FIG. 8. [Figure 10] FIG. 5 is a schematic cross-sectional view taken along the line BB of FIG. 4. [Figure 11] FIG. 11 is a partially enlarged schematic view of point b in FIG. [Figure 12] FIG. 5 is a schematic diagram of the structure in which the substrate is hidden in FIG. 4. [Figure 13] FIG. 13 is a schematic structural diagram of the outer ring of the substrate of FIG. [Figure 14] 14 is a schematic diagram showing the structure of the substrate outer ring of FIG. 13. [Figure 15] 1 is a perspective schematic view of a rotating component according to an embodiment of the present invention; [Figure 16] FIG. 16 is a schematic diagram of the structure in which the cover plate is hidden in FIG. 15. [Figure 17] FIG. 16 is a schematic structural diagram of the cover plate of FIG. 15. [Figure 18] FIG. 16 is a schematic structural diagram of the bottom plate of FIG. [Figure 19] 3A and 3B are schematic diagrams showing the three-dimensional structure of a substrate fixing part according to an embodiment of the present invention. [Figure 20-21] 1 is a schematic diagram of a substrate in a stable state after being placed on a substrate placement mechanism according to an embodiment of the present invention; DETAILED DESCRIPTION OF THE INVENTION

[0020] The above solution will be further described below in conjunction with specific embodiments.It should be understood that these embodiments are used to illustrate the present invention, but are not intended to limit the scope of the present invention.The operating conditions used in the examples can be further adjusted according to the conditions of specific manufacturers, and the operating conditions not specified are usually those in routine experiments.

[0021] This application discloses a substrate mounting mechanism, a tray assembly, and a silicon carbide epitaxial growth apparatus. The substrate mounting mechanism comprises a substrate outer ring, a substrate inner ring, and a substrate fixing portion. The substrate inner ring has a hollow region in the center, the substrate outer ring is sleeved onto the substrate inner ring, and the substrate outer ring overlaps the substrate inner ring. The substrate fixing portion is located below the substrate inner ring. The substrate fixing portion is provided with a support portion, and the protrusions on the substrate inner ring side of the support portion are located in the hollow region. The support portion comprises discrete protrusions or sub-protrusions, which are used to support the substrate. This design reduces the phenomenon of flying discs or pieces occurring during epitaxial growth of the substrate and improves temperature uniformity on the substrate side to ensure the quality of the grown epitaxial layer. The substrate size is 4 inches, 6 inches, 8 inches, or 12 inches. The substrate (also called a wafer) may be a silicon substrate, silicon carbide substrate, gallium nitride substrate, diamond substrate, boron nitride substrate, or gallium oxide substrate.

[0022] Next, the substrate mounting mechanism, tray assembly, and silicon carbide epitaxial apparatus proposed in the present application will be described with reference to FIGS.

[0023] FIG. 3 is a schematic diagram of a three-dimensional structure of a tray assembly according to an embodiment of the present invention, which includes a substrate placement mechanism 100 and a rotating part 150. As shown in FIG.

[0024] The substrate mounting mechanism 100 is for mounting the substrate 200 (a schematic top view after the substrate 200 has been mounted is shown in FIG. 4).

[0025] The substrate placement mechanism 100 is mounted on a rotating part 150 and is driven by the rotating part 150 to rotate the substrate placement mechanism 100 and thereby rotate the substrate. Preferably, the rotating part 150 is connected to a driving part (e.g., a driving motor, not shown), and the rotating part is rotated based on the driving of the driving part.

[0026] An isometric cross-sectional view of the tray assembly at AA in FIG. 4 is shown in FIG. 5, and a cross-sectional view is shown in FIG.

[0027] The substrate mounting mechanism 100 includes a substrate outer ring 110, a substrate inner ring 120, a support ring 140, and a base 130. The center of the substrate inner ring 120 is a hollow area for accommodating the substrate, The substrate outer ring 110 is sleeved onto the substrate inner ring 120, and the substrate outer ring 110 is placed over the substrate inner ring 120, The substrate 130 is hollow and ring-shaped, and has a first clamping portion 131 that protrudes along the axial direction on one side, a first receiving portion 132 on the same side as the first clamping portion 131, and a second receiving portion 133 opposite the first receiving portion 132.

[0028] The first housing 132 accommodates the support ring 140. One side of the support ring 140 has a protrusion 141 extending along the axial direction. The protrusion 141 abuts against (supports) the substrate 200 placed inside. The protrusion 141 on the outer ring side of the substrate abuts against the hollow region, supporting the placed substrate. Preferably, the protrusion 141 is cylindrical. See FIG. 9, which is a partially enlarged schematic diagram of point b in FIG. 8, or FIG. 19, which is a schematic diagram of the three-dimensional structure of the substrate fixing portion. Preferably, the substrate fixing portion includes the support ring 140. In other embodiments, the substrate fixing portion includes the support ring and the substrate, and the support ring and the substrate may be designed as a single unit. Preferably, the combination of the protrusion 141 is circular, and its diameter is smaller than the diameter (outer diameter) of the substrate. The protrusion 141 may be a geometric protrusion, such as a truncated cone, a protrusion formed by discontinuous rings, a rectangular table, or a trapezoidal table. This design minimizes the contact area between the protrusions and the substrate, reducing the heat transfer to the substrate via the protrusions generated by the heater of the rotating unit 150 during the epitaxial reaction. This reduces temperature variations in the contact area, improving temperature uniformity on the substrate side (within 2° of the temperature difference between the center and edge of the substrate). This improves the thickness and concentration uniformity of the grown epitaxial wafer. The axial depth / thickness of the first receiving unit 132 is the same as or approximately the same as the axial thickness of the support wheel 140 (excluding the height of the protrusions). After the support wheel 140 is placed in the first receiving unit 132, its upper surface is flush with or approximately flush with the upper surface 130a of the substrate 130. The substrate outer ring is overlapped with the substrate outer ring, i.e., the substrate outer ring is partially pressed against the substrate outer ring. In this way, the substrate outer ring deforms due to the temperature rise during epitaxial growth, but this deformation does not affect the substrate outer ring, thereby avoiding the problem of disks or pieces flying off when the substrate is inserted under the substrate outer ring.

[0029] FIG. 6 shows a cross-sectional view of the tray assembly at a specific viewing angle, FIG. 7 shows a partial enlarged view of point a in FIG. 6 , and FIGS. 8 and 9 show variations of the embodiment of FIG. 7 . FIG. 8 is a schematic cross-sectional view of the substrate mounting mechanism of the embodiment, and FIG. 9 is a partial enlarged view of point c in FIG. 8 . One side of the support wheel 240 is provided with a protrusion 241 extending along the axial direction. The protrusion 241 may be continuous (the protrusion 241 is ring-shaped as a whole). The protrusion 241 is provided with sub-protrusions 2411, and a recess is provided between two adjacent sub-protrusions 2411. The sub-protrusions 2411 are provided to reduce the contact area with the substrate, reduce temperature spikes formed at the contact points (temperature spikes do not contribute to process temperature field adjustment), and ensure that the temperature difference between the center side of the substrate and the edge side of the substrate is within 2°C. In other embodiments, the protrusions 241 may be separate, or the separate protrusions 241 may be combined with the sub-protrusions 2411 to further reduce the contact area with the substrate. This ensures that the temperature difference between the center and edge of the substrate is within 2°C during the epitaxial process, ensuring support.

[0030] A first protrusion 111 extending radially is formed on the inner side of the substrate outer ring 110, and the thickness H2 of the first protrusion 111 is smaller than the thickness H1 of the substrate outer ring 110. Preferably, the thickness H2 of the first protrusion 111 is half the thickness H1 of the substrate outer ring 110.

[0031] The outer side of the substrate inner ring 120 is provided with a second protrusion 121 extending radially outward. The thickness H3 of the second protrusion 121 is smaller than the thickness H4 of the substrate outer ring 120. The inner side of the substrate inner ring 120 has a positioning portion 122 (sometimes called a cutting edge), each with a transition portion 122a. The transition portion has a rounded corner 122A1 or a beveled edge 122A2. Due to the action of rotational centrifugal force, the positioning edge 210 of the substrate contacts the rounded corner 122A1 of the transition portion 122A1 of the substrate inner ring 120 (see FIG. 20), or the inner ring 120 of the substrate. The angled direction of the rounded corner or transition portion 122a and the sharp corner 211 of the substrate 200 are not constrained, preventing the inner ring of the substrate from being attached.

[0032] When the substrate outer ring 110 and the substrate inner ring 120 are assembled, the first protrusion 111 abuts the second protrusion 121, and the first protrusion 111 is positioned above the second protrusion 121 (the substrate inner ring is pressed down by its own weight), and there is an accommodating cavity between the second protrusion 121 and the substrate outer ring 110 (because the radial extension length of the first protrusion 111 is longer than the radial extension length of the second protrusion 121, after overlapping, the first protrusion 111, the second protrusion 121, and the substrate outer ring 110 are assembled to form an accommodating cavity for arranging the first clamping portion 131), and the accommodating cavity is used to arrange the first clamping portion 131. In this embodiment, the combined thickness of the first protrusion 111 and the second protrusion 121 is the same as or substantially the same as the thickness of the substrate outer ring 110 or the thickness of the substrate inner ring 120. By arranging the first protrusion 111 above the second protrusion 121, the substrate outer ring is deformed due to the temperature rise during epitaxial growth, but this deformation does not affect the position of the substrate inner ring relative to the substrate, thereby avoiding the problem of disks and pieces flying off when the substrate is inserted below the substrate inner ring.On the other hand, by arranging the first protrusion 111 above the second protrusion 121, the substrate inner ring can be pressed by the weight of the substrate outer ring 110, preventing disks and pieces from flying off.

[0033] A first connecting portion 153 is provided on one side of the rotating component 150. The first connecting portion 153 fits into a second connecting portion 172 of the bottom plate 170 to securely connect the rotating component 150 and the bottom plate 170 and prevent the rotating component and the bottom plate from sliding relative to each other. The first connecting portion 153 may be a notch, and the second connecting portion 172 may be a blocking portion having a shape that matches the notch. In another embodiment, the first connecting portion 153 may be a blocking portion, and the second connecting portion 172 may be a notch that matches the shape of the notch. It is sufficient that the first connecting portion 153 and the second connecting portion 172 are connected to prevent the rotating component and the bottom plate from sliding relative to each other.

[0034] The other side of the rotating component 150 (the side away from the first connecting portion 153) is provided with a flat portion 151 extending radially inward, and the flat portion 151 is provided with a first protruding rib 152 extending axially along the rotating component 150. The first protruding rib 152 is annular (when the protruding rib 152 is continuous), or the combination of the first protruding ribs 152 is annular (when the protruding ribs 152 are discontinuous). A second protruding rib 151a is formed at the end of the flat portion 151 extending radially therefrom, and a second notch 151a1 is formed in the second protruding rib 151a, and the thickness of the second protruding rib 151a is thinner than the thickness of the flat portion 151 (when viewed in the axial direction of the rotating component 150). In this embodiment, there are two second notches 151a1, but in other embodiments, the number of second notches 151a1 may be one, three, four, or more. The rotating part 150 is provided with a heater (not shown), which may be a graphite heater.

[0035] The bottom plate 170 has a cylindrical main body 171, one side of which is provided with a third protrusion 173 and a second connection portion 172, and a through hole 174 for connecting a hollow rotating shaft 180 is provided in the center of the bottom plate 170.

[0036] The cover plate 160 is disposed on a side of the rotating member 150 away from the bottom plate 170, The cover plate 160 has a main body 160a, and a third protruding rib 161 extending radially is provided at the end of the main body 160a, the thickness of the third protruding rib 161 being smaller than the thickness of the main body 160a (along the axial direction of the cover plate 160), and a protrusion 160b extending radially is provided at the end of the main body 160a.

[0037] In one embodiment, a fourth protruding rib 162 is disposed on the side of the main body 160a near the third protruding rib 161. The fourth protruding rib 162 is used to abut against the support ring 140, with a gap e between the bottom of the support ring 140 and the main body 160a. In this embodiment, the width of the fourth protruding rib 162 (in the radial direction of the main body 160a) is smaller than the axial thickness of the support ring 140. This design reduces the contact area between the fourth protruding rib 162 and the support ring 140, reducing the heat transferred to the support ring 140 through the fourth protruding rib 162 during the epitaxial reaction and reducing the formation of local temperature spikes. In another embodiment, the fourth protruding rib 162 has sub-protrusions, with recesses between two adjacent sub-protrusions (see FIG. 9 for the structure), reducing the contact area with the support ring 140 and reducing the temperature spikes formed at the contact points. In another embodiment, the fourth protruding rib 162 may be omitted. After the support wheel 140 is placed in the first receiving portion 132, a gap is provided between the bottom of the support wheel 140 and the body 160a to prevent heat from the body 160a from being directly transferred to the support wheel 140.

[0038] A step is provided on the side of the main body 160a facing the fourth protruding rib 162, away from the third protruding rib 161. When a substrate is placed on top of the main body 160a, a gap d exists between the substrate (bottom) and the surface of the main body 160a. The distance between the substrate (bottom) and the surface of the main body 160a is not completely uniform (e.g., it may gradually increase or decrease from the inside to the outside, or may vary periodically or variably periodically). This improves heat dissipation from the main body 160a to the substrate and ensures uniformity of the temperature field on the substrate side. When the cover plate is coupled to the rotating component 150, the protrusion 160b is embedded in the second notch 151a1. After relative transformation, the protrusion 160b abuts against the second protruding rib 153, connecting the cover plate to the rotating component.

[0039] In one embodiment, a fifth protruding rib 163, a step 164, and a recess 165 are sequentially provided on the fourth protruding rib 162 side of the main body 160a, away from the third protruding rib 161. The recess 165 is located at the center of the main body 160a. When a substrate is placed on top of the main body 160a, the distance (gap) from the fifth protruding rib 163, the step 164, and the recess 165 to the substrate (bottom) gradually narrows, improving heat dissipation from the main body 160a to the substrate and ensuring uniformity of the temperature field on the substrate side. In this way, the grown epitaxial wafer has a uniform thickness and doping concentration. In this embodiment, the protruding height of the fifth protruding rib 163 is greater than the protruding height of the fourth protruding rib 162 (as viewed in the axial direction of the main body 160a).

[0040] The present invention provides a silicon carbide epitaxial apparatus having a reaction chamber. The reaction chamber is columnar and has an atomizing element at its top. The atomizing element is connected to a gas source for providing an epitaxial reaction via a pipeline. The bottom side of the reaction chamber has the aforementioned tray assembly. When the reaction chamber is operating, gas atomized by the atomizing element flows toward the tray assembly and reacts on the surface of a substrate on the tray assembly to grow a thin film (such as a single-crystal thin film, also known as epitaxy). When the reaction chamber is operating, the tray assembly rotates at a constant speed.

[0041] The above embodiments are intended to explain the technical concepts and features of the present application, and are intended to enable those skilled in the art to understand and implement the contents of the present application, but cannot be used to limit the scope of protection of the present application. Any equivalent changes or modifications made in accordance with the spirit of the present application shall fall within the scope of protection of the present application.

Claims

1. A substrate mounting mechanism for supporting a substrate in an epitaxial apparatus, comprising: a substrate outer ring, a substrate inner ring, and a substrate fixing portion; A hollow area is provided in the center of the substrate inner ring, a positioning portion is provided inside the substrate inner ring, and transition portions are provided on both sides of the positioning portion, The substrate outer ring is sleeved onto the substrate inner ring, and the substrate outer ring overlaps the substrate inner ring, and a first protrusion extending radially inside the substrate outer ring is provided, and the axial thickness of the first protrusion is smaller than the axial thickness of the substrate outer ring; a second protruding portion extending radially outward from the substrate inner ring, an axial thickness of the second protruding portion being smaller than an axial thickness of the substrate outer ring, the first protruding portion abutting the second protruding portion, and the first protruding portion being located above the second protruding portion; A substrate mounting mechanism characterized in that the substrate fixing portion is located below the substrate inner ring, a support portion is provided on the substrate fixing portion, the orthogonal projection of the support portion onto the substrate inner ring is projected onto the hollow area, and the support portion has discrete protrusions or sub-protrusions, and the protrusions or sub-protrusions are for supporting the substrate.

2. the substrate placement mechanism further includes a support wheel; the support ring is disposed inside the inner ring, the support portion is disposed on the support ring, and an orthogonal projection of the support portion onto the substrate inner ring is projected onto the cavity region; or the substrate fixing portion includes a support ring and a substrate; 2. The substrate placing mechanism of claim 1, wherein the substrate is hollow and ring-shaped, and has a first receiving portion, a second receiving portion, and a first clamping portion arranged on the same side, the first clamping portion protruding along the axial direction, the second receiving portion arranged opposite the first receiving portion, the first receiving portion for accommodating a support wheel, and a protrusion extending along the axial direction on one side of the support wheel for supporting the placed substrate.

3. 2. The substrate support mechanism of claim 1, wherein the transition portion has rounded corners and / or beveled edges.

4. The substrate mounting mechanism according to claim 1 , wherein the plate fixing portion includes a boss having a geometric shape such as a cylindrical shape, a truncated cone shape, a boss formed by a discontinuous ring, a rectangular truncated shape, or a trapezoidal truncated shape.

5. 2. The substrate mounting mechanism according to claim 1, wherein a receiving cavity is provided between the second protrusion and the substrate outer ring, and the receiving cavity is for placing a first clamping part therein.

6. 1. A tray assembly comprising: A tray assembly comprising a rotating part, a cover plate provided on one side of the rotating part, and a substrate placement mechanism according to any one of claims 1 to 5 mounted on the cover plate.

7. a flat portion extending radially inward is provided on one side of the rotating component, a second protruding rib extending radially is provided at an end of the flat portion, a notch extending axially is formed in the second protruding rib, and the axial thickness of the second protruding rib is smaller than the axial thickness of the flat portion; 7. The tray assembly of claim 6, wherein the cover plate has a body, a third protruding rib extending radially from an end of the body, and at least one protrusion, the protrusion being embedded in the notch and abutting the second protruding rib.

8. 8. The tray assembly of claim 7, wherein the flat portion has a first protruding rib extending along the axial direction of the rotating part, the first protruding rib being annular, or a combination of first protruding ribs being annular.

9. 8. The tray assembly of claim 7, wherein a fourth protruding rib is disposed on a side of the main body closer to the third protruding rib, and a step portion is disposed on a side of the fourth protruding rib away from the third protruding rib, and the step portion is configured such that when a substrate is present on the upper side of the main body, a gap between the surface of the main body and the substrate changes.

10. 1. A silicon carbide epitaxial device comprising: a reaction chamber with a spray element at the top; A silicon carbide epitaxial apparatus, characterized in that the tray assembly according to any one of claims 6 to 9 is provided at the bottom of the reaction chamber.

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