Tray assembly, bearing device and semiconductor process equipment

Abstract

The utility model provides a tray assembly, a bearing device and semiconductor process equipment. The tray assembly comprises a tray and a pressing ring. The compression ring covers the tray, the orthographic projection of the compression ring on the top surface of the tray coincides with the circumferential edge area of the top surface of the tray, and the inner circumferential surface of the compression ring and the upper surface of the tray jointly define a mounting space; a plurality of supporting convex parts are convexly arranged on the upper surface of the tray, all the supporting convex parts are arranged in the mounting space, all the supporting convex parts are arranged in at least one circle on the upper surface of the tray, the center of each circle of supporting convex part is located on the central axis of the pressing ring, and at least one circle of supporting convex part is used for supporting a wafer; and each supporting convex part is configured to be a cambered surface in contact with the wafer. When semiconductor process equipment adopts the tray assembly provided by the utility model, the heating modes of the central area and the edge area of the wafer are consistent in the buckling deformation process of the wafer, and the temperature uniformity of the surface of the wafer is effectively improved, so that the uniformity of a film is improved.

Description

Technical Field

[0001] The utility model relates to the field of semiconductor manufacturing, and in particular to a tray assembly, a carrying device and semiconductor process equipment. Background Art

[0002] Chemical Vapor Deposition (CVD) is a vapor phase epitaxial growth technology. Its principle is to pass a process gas mixed with compounds containing thin film elements into a process chamber. The process gas flows through the surface of the substrate heated to a higher temperature. The compound undergoes a chemical reaction on the substrate surface and grows epitaxially into a compound single crystal thin film. Temperature is an important indicator in the semiconductor preparation process, and the uniformity of temperature directly affects the uniformity of film thickness.

[0003] In existing semiconductor process equipment, a tray assembly is usually provided in the process chamber to carry wafers. Specifically, the tray of the tray assembly includes a body and a boss protruding from the body, and the side of the boss facing away from the body is a carrying surface for placing the wafer.

[0004] However, the uniformity of the thin film produced by using the semiconductor process equipment is poor. Utility Model Content

[0005] The utility model aims to solve at least one of the technical problems existing in the prior art, and proposes a tray assembly, a carrying device and a semiconductor process equipment.

[0006] The first aspect of the utility model provides a tray assembly, comprising: a tray and a pressure ring; the pressure ring is pressed onto the tray, the orthographic projection of the pressure ring on the upper surface of the tray overlaps with the circumferential edge area of ​​the upper surface of the tray, and the inner circumferential surface of the pressure ring and the upper surface of the tray together form an installation space; a plurality of supporting protrusions are arranged on the upper surface of the tray, all of the supporting protrusions are arranged in the installation space, all of the supporting protrusions are arranged in at least one circle on the upper surface of the tray, the center of each circle of supporting protrusions is located on the central axis of the pressure ring, and at least one circle of supporting protrusions is used to support a wafer; and each supporting protrusion is configured to have an arc surface as a contact surface with the wafer.

[0007] In the tray assembly as described above, the supporting protrusion comprises a supporting portion, the supporting portion has a curved surface, and the cross-sectional shape of the supporting portion is circular, semicircular, arc-shaped or elliptical.

[0008] In the tray assembly as described above, the supporting protrusion further comprises a fixing seat located below the supporting portion, the bottom of the fixing seat is fixedly connected to the upper surface of the tray, and the top of the fixing seat is fixedly connected to the supporting portion.

[0009] In the tray assembly as described above, the fixing seat is a truncated cone structure or a prism structure; the cross-sectional area of ​​the fixing seat in a direction perpendicular to the central axis of the pressure ring gradually decreases from the bottom to the top of the fixing seat.

[0010] The tray assembly as described above, wherein the thermal conductivity of the supporting protrusion is lower than the thermal conductivity of the tray.

[0011] In the tray assembly as described above, a coating is provided on the outer surface of the supporting protrusion, and the thermal conductivity of the coating is lower than the thermal conductivity of the tray.

[0012] In the tray assembly as described above, a circle of supporting protrusions is used to support the wafer, and a plurality of supporting protrusions arranged in a circle are spaced apart and distributed around the central axis of the pressure ring.

[0013] In the tray assembly as described above, the height of one circle of supporting protrusions for supporting the wafer along the vertical direction is greater than or equal to 350 μm and less than or equal to 400 μm.

[0014] The tray assembly as described above, wherein all the supporting protrusions are arranged in a plurality of circles on the upper surface of the tray, and the plurality of circles of supporting protrusions are arranged at intervals along the radial direction of the tray;

[0015] Along the radial direction of the tray, the height of each circle of supporting protrusions gradually increases from the center of the tray to the edge of the tray, and the outermost circle of supporting protrusions is used to support the wafer; or,

[0016] Along the radial direction of the tray, the height of each circle of supporting protrusions gradually decreases from the center of the tray to the edge of the tray, and the innermost circle of supporting protrusions is used to support the wafer.

[0017] In the tray assembly as described above, the height difference between two adjacent circles of supporting protrusions is less than 50 μm; and / or, the two adjacent circles of supporting protrusions are staggered along the circumferential direction of the pressure ring.

[0018] The second aspect of the utility model provides a bearing device, comprising: a base and any one of the tray assemblies provided by the first aspect of the utility model, the tray assembly is stacked on the base, and the base is used to bear the tray assembly.

[0019] A third aspect of the present invention provides a semiconductor process equipment, comprising: a process chamber and any one of the carrying devices provided by the second aspect of the present invention, wherein a tray assembly of the carrying device is located in the process chamber.

[0020] The utility model has the following beneficial effects:

[0021] When the semiconductor process equipment equipped with the tray assembly provided by the utility model is used to perform the epitaxial process, the heating method of the central area and the edge area of ​​the wafer is always consistent during the process of the wafer warping and deformation. The tray can continuously and stably heat the central area and the edge area of ​​the wafer by heat radiation, so that the temperature difference between the front and back of the wafer is relatively stable during the warping and deformation process, effectively reducing the generation of thermal stress, and further effectively inhibiting the edge of the wafer from continuing to warp and deform. In this way, the temperature uniformity of the wafer surface can be effectively improved, thereby improving the uniformity of the film. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 A schematic diagram of a tray assembly in the related art;

[0023] Figure 2 A top view of a tray in a tray assembly in the related art;

[0024] Figure 3 A top view of a pressure ring in a tray assembly in the related art;

[0025] Figure 4 is a schematic diagram of another tray assembly in the related art;

[0026] Figure 5 A schematic diagram of a tray assembly provided in Example 1 of the present application;

[0027] Figure 6 A top view of a tray assembly provided in Embodiment 1 of the present application;

[0028] Figure 7 A schematic cross-sectional view of a supporting protrusion in a tray assembly provided in Embodiment 1 of the present application;

[0029] Figure 8 A top view of a supporting protrusion in a tray assembly provided in Embodiment 1 of the present application;

[0030] Fig. 9 A schematic diagram of a tray assembly provided in Embodiment 2 of the present application;

[0031] Fig.10 A top view of a tray assembly provided in Embodiment 2 of the present application;

[0032] Fig.11 A schematic diagram of another tray assembly provided in Example 2 of the present application.

[0033] Description of reference numerals:

[0034] 100-tray assembly;

[0035] 10-tray; 11-body; 12-boss;

[0036] 20-pressure ring; 21-first annular body; 22-second annular body;

[0037] 30-supporting protrusion; 31-supporting portion; 32-fixing seat;

[0038] 200-chip. DETAILED DESCRIPTION

[0039] Figure 1 is a schematic diagram of a tray assembly in the related art, Figure 2 is a top view of a tray in a tray assembly in the related art, Figure 3 FIG. 1 is a top view of a pressure ring in a tray assembly in the related art. Figures 1 to 3 In the related art shown, the tray assembly 100a includes a tray 10a and a pressure ring 20a, and the pressure ring 20a is stacked on the circumferential edge of the tray 10a. The tray 10a includes a body 11a and a boss 12a protruding from the body 11a, and the side of the boss 12a facing away from the body 11a is a bearing surface for bearing a wafer 200. Part of the pressure ring 20a overlaps the outer peripheral edge of the boss 12a, and the wafer 200 is located in the middle through hole 23a of the pressure ring 20a and fits the bearing surface. However, the uniformity of the thin film produced by the semiconductor process equipment equipped with the tray assembly 100a is poor.

[0040] After careful research, the inventor of the present application found that the reason for this technical problem is that in order to increase the temperature of the wafer to the process temperature of the chemical vapor deposition process, the tray needs to be heated. Since the wafer is attached to the bearing surface, the tray transfers heat to the wafer by heat conduction. When the wafer material is different from the film material, that is, the process type is heteroepitaxial, due to the mismatch of the lattice constants of the wafer material and the film material, thermal stress is generated between the film and the wafer during the process, making the edge of the wafer prone to warping and deformation, causing the central area or edge area of ​​the wafer to move away from the tray and change from heat conduction to heat radiation for heating. Because the heat transfer capacity of the heat radiation method is weaker than that of the heat conduction method, the temperature difference between the front and back of the wafer increases, resulting in greater thermal stress on the surface of the wafer, which further promotes the warping and deformation of the edge of the wafer. In this way, there is a large difference in temperature between the edge area and the central area of ​​the wafer, and the uniformity of the surface temperature of the wafer is poor, thereby affecting the uniformity of the film.

[0041] It should be understood that, depending on the difference in thermal expansion coefficients between the chip material and the film material, the edge of the chip may warp upward, in which case the center area of ​​the chip is concave into an arc; or, the edge of the chip may warp downward, in which case the center area of ​​the chip is convex into an arc.

[0042] Figure 4Schematic diagram of another tray assembly in the related art. In order to solve this technical problem, the related art provides another tray assembly 100b, such as Figure 4 As shown, an annular protrusion 30b is protruding from the upper surface of the tray 10b, and the annular protrusion 30b is located in the middle through hole of the pressure ring 20b. When the tray assembly 100b is used to carry a wafer 200, the wafer 200 can be placed in the middle through hole, and the back side of the edge of the wafer 200 is in contact with the upper surface of the annular protrusion 30b.

[0043] When the semiconductor process equipment equipped with the tray assembly 100b is used to perform epitaxial process, when the temperature of the wafer 200 is room temperature, no thermal stress is generated on the surface of the wafer 200, and the tray 10b transfers heat to the edge area of ​​the wafer 200 through the annular protrusion 30b by heat conduction, and the tray 10b transfers heat to the center area of ​​the wafer 200 by heat radiation. When the temperature of the wafer 200 is high and thermal stress is generated on the surface of the wafer 200, if the edge of the wafer 200 is warped and deformed upward, the edge area of ​​the wafer 200 is away from the annular protrusion 30b, and the tray 10b transfers heat to the edge area of ​​the wafer 200 through the annular protrusion 30b by heat radiation, so that the heating method of the edge area and the center area of ​​the wafer 200 is consistent. In this way, the temperature uniformity of the surface of the wafer 200 is improved, thereby improving the uniformity of the thin film.

[0044] However, the following problems are unavoidable when the semiconductor process equipment equipped with the tray assembly 100b is in operation.

[0045] First, when the wafer 200 is heated to a relatively high temperature and thermal stress is generated on the surface of the wafer 200, if the edge of the wafer 200 is warped downward, the central area of ​​the wafer 200 is away from the upper surface of the tray 10b, and the edge area of ​​the wafer 200 is still in contact with the annular protrusion 30b. Accordingly, the tray 10b transfers heat to the edge area of ​​the wafer 200 by heat conduction and transfers heat to the central area of ​​the wafer 200 by heat radiation. It can be seen that during the warping and deformation of the wafer 200, the heating methods of the edge area and the central area of ​​the wafer 200 are still different, and the temperature uniformity of the surface of the wafer 200 is poor, thereby affecting the uniformity of the film. In other words, using a wafer having Figure 4 The semiconductor process equipment of the tray assembly 100 b shown in the figure is used to perform epitaxial process, but cannot solve the problem of poor uniformity of the film in the application scenario where the edge of the wafer 200 is warped downward.

[0046] Secondly, if the chip 200 is warped due to thermal stress, the radial size of the chip 200 becomes smaller, and the contact between the chip 200 and the annular protrusion 30b gradually changes from surface contact to line contact, so that the contact stress between the chip 200 and the annular protrusion 30b increases, and stress concentration is prone to occur at the position on the chip 200 that contacts the annular protrusion 30b, which in turn causes the position on the chip 200 that contacts the annular protrusion 30b to be easily damaged, resulting in a cracking problem.

[0047] Third, there is a gap between the central area of ​​the wafer 200 and the upper surface of the tray 10b, and the contact between the edge area of ​​the wafer 200 and the annular protrusion 30b is surface contact, so the tray 10b transfers heat to the edge area of ​​the wafer 200 by heat conduction and transfers heat to the central area of ​​the wafer 200 by heat radiation. Since the heat transfer capacity of the heat radiation method is weaker than the heat transfer capacity of the heat conduction method, the temperature of the edge area of ​​the wafer 200 is higher than the temperature of the central area, and there is a large temperature difference between the central area and the edge area of ​​the wafer 200, which leads to the easy generation of thermal stress at the junction of the central area and the edge area of ​​the wafer 200. In this way, under the dual influence of the thermal stress at the junction of the central area and the edge area, and the local stress at the position where the wafer 200 contacts the annular protrusion 30b, when the edge of the wafer 200 warps and shrinks, the edge area is easily scratched by the edge of the annular protrusion 30b to form a slip line, and in severe cases, cracks may even be generated in the edge area of ​​the wafer 200.

[0048] Fourth, when the chip 200 is placed on the annular protrusion 30b, the chip 200 closes the space enclosed by the upper surface of the tray 10b and the inner circumference of the annular protrusion 30b. In this way, there is a pressure difference between the front and back sides of the chip 200. When the tray assembly 100b rotates during the process, the chip 200 is easy to shift, and in severe cases, it may even cause flying chips.

[0049] In view of this, the present application provides a tray assembly, a carrying device and a semiconductor process equipment. In order to enable those skilled in the art to better understand the technical solution of the utility model, the tray assembly, the carrying device and the semiconductor process equipment provided by the utility model are described in detail below in conjunction with the accompanying drawings.

[0050] Embodiment 1

[0051] The embodiment of the present application provides a semiconductor process equipment, which can implement processes not limited to plasma chemical vapor deposition (PCVD), but can also be used to implement other chemical vapor deposition process types such as metal organic compound chemical vapor deposition technology (MOCVD) and low pressure chemical vapor deposition (LPCVD).

[0052] The semiconductor process equipment comprises a process chamber and a carrying device, wherein the carrying device comprises a tray assembly and a base, wherein the tray assembly is located inside the process chamber for carrying a wafer, the tray assembly is stacked on the base, and the base is used to carry the tray assembly.

[0053] In some embodiments, part of the base can extend from the inside of the process chamber to the outside of the process chamber and be connected to a drive motor. The drive motor is used to drive the base to rotate, thereby driving the tray assembly to rotate, and the wafer placed on the tray assembly rotates accordingly, so as to improve the uniformity of the process.

[0054] In some embodiments, the semiconductor process equipment further includes a heater and a power source disposed outside the process chamber, the heater being disposed below the tray assembly, for example, being disposed inside the base, and the heater being electrically connected to the power source. Thus, the power source supplies power to the heater, so that the heater is heated, and the heat of the heater is transferred to the tray assembly to heat the tray assembly and the wafer.

[0055] The tray assembly provided in this embodiment is described in detail below with reference to the accompanying drawings.

[0056] Figure 5 This is a schematic diagram of a tray assembly provided in Example 1 of the present application. Figure 6 This is a top view of the tray assembly provided in Example 1 of the present application. Figure 5 and Figure 6 The tray assembly 100 includes a tray 10 and a pressure ring 20 .

[0057] The structure of the tray 10 can be implemented in various ways. For example, the tray 10 can be a cylindrical structure. Figure 5 As shown, the tray 10 may further include a body 11 and a boss 12 protruding from the body 11, the boss 12 and the body 11 may both be cylindrical structures, and the outer diameter of the boss 12 is smaller than the outer diameter of the body 11, so that a step is formed on the tray 10. Of course, in other embodiments, the body 11 may also be replaced to include a plurality of cylinders, the plurality of cylinders are stacked in sequence, and the outer diameters of the cylinders gradually increase from top to bottom.

[0058] The pressing ring 20 is an annular structure with a central through hole. The pressing ring 20 is pressed on the tray 10, and the central axis of the pressing ring 20 coincides with the central axis of the tray 10. Figure 5 As shown, the pressing ring 20 may specifically include a first annular body 21 and a second annular body 22 which are coaxially arranged, the first annular body 21 being stacked on the second annular body 22, and the inner diameter of the first annular body 21 being smaller than the inner diameter of the second annular body 22. When the pressing ring 20 is pressed onto the tray 10, the first annular body 21 is pressed against the upper surface of the boss 12, and the second annular body 22 surrounds the outer periphery of the boss 12 and is pressed against the upper surface of the body 11.

[0059] The orthographic projection of the pressure ring 20 on the upper surface of the tray 10 also overlaps with the circumferential edge area of ​​the upper surface of the tray 10. In this article, the upper surface of the tray 10 refers to the side of the tray 10 facing the wafer. This should be understood in a broad sense. Figure 5 As shown in the example, the outer diameter of the first annular body 21 is larger than the outer diameter of the body 11. At this time, the orthographic projection of the pressure ring 20 on the upper surface of the tray 10 partially overlaps with the circumferential edge area of ​​the upper surface of the tray 10, and the pressure ring 20 exceeds the outer circumference of the body 11. Alternatively, when the outer diameter of the first annular body 21 is equal to the outer diameter of the body 11, it can be understood that the orthographic projection of the pressure ring 20 on the upper surface of the tray 10 completely overlaps with the circumferential edge area of ​​the upper surface of the tray 10. Alternatively, when the outer diameter of the first annular body 21 is smaller than the outer diameter of the body 11, it can be understood that the orthographic projection of the pressure ring 20 on the upper surface of the tray 10 falls within the circumferential edge area of ​​the upper surface of the tray 10.

[0060] A plurality of supporting protrusions 30 are protruding from the upper surface of the tray 10, and all supporting protrusions 30 are arranged in the installation space enclosed by the inner circumference of the pressing ring 20 and the upper surface of the tray 10. In other words, all supporting protrusions 30 are located in the middle through hole of the pressing ring 20. Figure 6 As shown, all the supporting protrusions 30 are arranged in a circle on the upper surface of the tray 10 around the central axis of the pressing ring 20. That is, the center of the circle of supporting protrusions 30 is located on the central axis of the pressing ring 20.

[0061] The tray assembly 100 of this embodiment can be used to carry a wafer 200. Specifically, the wafer 200 is placed on the ring support protrusions 30, and the ring support protrusions 30 are used to support the wafer 200. In addition, each support protrusion 30 is configured to have a curved surface in contact with the wafer 200, so that the curved surface and the wafer 200 are in point contact.

[0062] It should be pointed out that the support protrusion 30 being arranged in the installation space should also be understood in a broad sense.

[0063] For example, it can be understood that the supporting protrusion 30 is completely accommodated in the installation space. Figure 5 In one case shown, the sum of the height H of the support protrusion 30 along the extension direction of the central axis of the pressure ring 20 and the thickness of the wafer 200 is less than the distance between the upper surface of the pressure ring 20 and the upper surface of the tray 10 along the vertical direction, and the wafer 200 is also completely accommodated in the installation space, the front of the wafer 200 does not exceed the upper surface of the pressure ring 20, and the pressure ring 20 also surrounds the outer periphery of the wafer 200. Among them, the extension direction of the central axis of the pressure ring 20 is parallel to the vertical direction, and the vertical direction is Figure 5It is shown as Z. Alternatively, in another case, part of the wafer 200 is accommodated in the installation space and part of the wafer 200 protrudes out of the installation space.

[0064] For another example, it can also be understood that part of the supporting protrusion 30 is accommodated in the installation space, and the top is extended out of the installation space. In this case, the chip 200 is completely located outside the installation space.

[0065] The position where the supporting protrusion 30 contacts the wafer 200 is not limited. Figure 5 and Figure 6 As shown, the diameter of the circle formed by all the supporting protrusions 30 is r, and the diameter of the wafer 200 is R, where r is smaller than R and close to R, so that when the wafer 200 is placed on the supporting protrusions 30, the edge area of ​​the wafer 200 is located outside the circle formed by the supporting protrusions 30. Alternatively, r may also be much smaller than R, so that the supporting protrusions 30 abut against the central area of ​​the wafer 200.

[0066] Use Figure 5 The semiconductor process equipment of the tray assembly 100 shown is used to carry out the epitaxial process. When the temperature of the chip 200 is at room temperature, no thermal stress is generated on the surface of the chip 200. There are gaps between the central area and the edge area of ​​the chip 200 and the upper surface of the tray 10. The tray 10 transfers heat to the central area and the edge area of ​​the chip 200 by thermal radiation.

[0067] During the process, the temperature of the wafer 200 rises, and thermal stress is generated on the surface of the wafer 200, causing the edge of the wafer 200 to warp and deform. If the edge of the wafer 200 warps and deforms upward, the distance between the edge area of ​​the wafer 200 and the upper surface of the tray 10 along the vertical direction Z increases, and the tray 10 still transfers heat to the edge area of ​​the wafer 200 by thermal radiation. At this time, although the central area of ​​the wafer 200 is concave downward, due to the gap between the wafer 200 and the upper surface of the tray 10, the concave central area is still not in contact with the tray 10, and the tray 10 still transfers heat to the central area of ​​the wafer 200 by thermal radiation.

[0068] If the edge of the chip 200 is warped downward, the distance between the central area of ​​the chip 200 and the upper surface of the tray 10 along the vertical direction Z increases, and the tray 10 still transfers heat to the central area of ​​the chip 200 by thermal radiation. At this time, although the edge area of ​​the chip 200 is warped downward, due to the gap between the chip 200 and the upper surface of the tray 10, the downward-warped edge area is still not in contact with the tray 10, and the tray 10 still transfers heat to the edge area of ​​the chip 200 by thermal radiation.

[0069] It can be seen that during the warping and deformation of the wafer 200, the heating methods of the central area and the edge area of ​​the wafer 200 are always consistent, and the tray 10 can continuously and stably heat the central area and the edge area of ​​the wafer 200 by heat radiation, so that the temperature difference between the front and back sides of the wafer 200 is relatively stable during the warping and deformation, effectively reducing the generation of thermal stress, and further effectively inhibiting the edge of the wafer 200 from continuing to warp and deform. In this way, the degree of warping and deformation at the edge of the wafer 200 is smaller, which effectively improves the temperature uniformity of the surface of the wafer 200, thereby improving the uniformity of the film.

[0070] Moreover, with Figure 4 Compared with the related technologies shown in the figure, when the tray assembly 100 of this embodiment is applied to the semiconductor process equipment, it can not only solve the problem that the edge of the chip 200 is warped upward, resulting in poor temperature uniformity and film uniformity on the surface of the chip 200, but also solve the problem that the edge of the chip 200 is warped downward, resulting in poor temperature uniformity and film uniformity on the surface of the chip 200.

[0071] It should also be noted that when the tray assembly 100 of this embodiment carries the wafer 200, the portion of the wafer 200 that contacts the supporting protrusion 30 receives the heat transferred by the tray 10 by heat conduction, and the portion of the wafer 200 that does not contact the supporting protrusion 30 receives the heat transferred by the tray 10 by heat radiation. At the same time, since the contact between the supporting protrusion 30 and the wafer 200 is point contact, Figure 4 Compared with the related technologies shown in the figure, the contact area between the tray assembly 100 and the chip 200 in this embodiment is smaller, so the surface temperature of the chip 200 is more uniform, and the temperature difference between the central area and the edge area of ​​the chip 200 is smaller, which can effectively reduce the thermal stress generated at the junction of the central area and the edge area of ​​the chip 200, thereby reducing the possibility of the chip 200 being affected by the thermal stress to generate slip lines, reducing the risk of cracks in the edge area of ​​the chip 200, and improving the yield of the chip 200.

[0072] In addition, by setting the contact surface between the support protrusion 30 and the wafer 200 as a curved surface, the wafer 200 slips relative to the curved surface during the warping deformation of the wafer 200, and the contact mode between the wafer 200 and the curved surface is always maintained as point contact, so the contact stress between the wafer 200 and the support protrusion 30 is relatively stable. In other words, before and after the wafer 200 is warped, the change in the contact stress between the wafer 200 and the support protrusion 30 is small. In this way, the probability of stress concentration at the position where the wafer 200 contacts the support protrusion 30 is greatly reduced, thereby reducing the risk of the wafer 200 contacting the support protrusion 30 and causing cracks due to damage.

[0073] In this embodiment, the influence of thermal stress and stress concentration on the wafer 200 is also reduced, the possibility of the wafer 200 generating slip lines is effectively reduced, the risk of cracks in the wafer 200 is reduced, and the yield of the wafer 200 is improved.

[0074] As disclosed in the tray assembly 100 , the material of the tray 10 and the material of the pressure ring 20 may be the same, for example, both are graphite.

[0075] In some embodiments, the plurality of support protrusions 30 arranged in a circle may be spaced and evenly distributed around the central axis of the pressure ring 20. Thus, the support protrusions 30 arranged in a circle can support the wafer 200, and the wafer 200 is evenly stressed.

[0076] Moreover, with this design, there is a gap between any two adjacent supporting protrusions 30 in a circle. That is, when the wafer 200 is placed on the tray assembly 100, the back side of the wafer 200, a circle of supporting protrusions 30 and the upper surface of the tray 10 do not form a closed space, so as to avoid a pressure difference between the front and back sides of the wafer 200, thereby effectively reducing the risk of the wafer 200 shifting or flying when the tray assembly 100 rotates.

[0077] The height H of each supporting protrusion 30 in a circle along the vertical direction Z is equal, and the height H of the supporting protrusion 30 along the vertical direction Z can be greater than or equal to 350μm and less than or equal to 400μm. In this way, while ensuring that the edge area and the center area of ​​the wafer 200 are heated by thermal radiation, the height of the supporting protrusion 30 is small, so that the wafer 200 placed on the supporting protrusion 30 is close to the tray 10, so that more heat can be transferred to the wafer 200, so that the temperature of the wafer 200 can meet the process temperature requirements of chemical vapor deposition.

[0078] It should be understood that the structures and sizes of the plurality of supporting protrusions 30 arranged in a circle can be the same or different, as long as each supporting protrusion 30 in a circle can support the wafer 200. The structure of one supporting protrusion 30 will be described in detail below.

[0079] Figure 7 This is a cross-sectional schematic diagram of the supporting protrusion 30 in the tray assembly 100 provided in the first embodiment of the present application. Figure 8 FIG. 1 is a top view of the support protrusion 30 in the tray assembly 100 provided in the first embodiment of the present application. Figure 7 and Figure 8 The supporting protrusion 30 may include a supporting portion 31 having a curved surface. When the wafer 200 is placed on the tray assembly 100 , the supporting portion 31 abuts against the back surface of the wafer 200 .

[0080] In the tray assembly 100 disclosed herein, the manners for achieving the curved surface of the support portion 31 include but are not limited to the following possibilities.

[0081] In a feasible way, please refer to Figure 7 and Figure 8 The cross-section of the support portion 31 is semicircular. In this example, the support portion 31 may be a hemispherical body. In this case, the support portion 31 is in point contact with the wafer 200 .

[0082] In another achievable manner, the cross-section of the support portion 31 is circular. In this example, the support portion 31 may be a sphere, and in this case, the support portion 31 is in point contact with the wafer 200 .

[0083] In another achievable manner, the cross-section of the support portion 31 is arc-shaped. In this example, the support portion 31 may be a plate-shaped structure bent into an arc.

[0084] In another achievable manner, the cross-sectional shape of the support portion 31 is elliptical. In this example, the support portion 31 may be an ellipsoid. In this case, the support portion 31 is in point contact with the wafer 200. Based on the embodiment in which the support protrusion 30 includes the support portion 31, please continue to refer to Figure 7 and Figure 8 The supporting protrusion 30 may further include a fixing seat 32, the fixing seat 32 is located below the supporting portion 31, the bottom of the fixing seat 32 is fixedly connected to the upper surface of the tray 10, and the top of the fixing seat 32 is fixedly connected to the supporting portion 31. By designing the fixing seat 32, the fixing seat 32 can play a stable supporting role for the supporting portion 31.

[0085] The materials of the fixing seat 32 and the supporting portion 31 may be the same or different. The connection between the bottom of the fixing seat 32 and the tray 10 may be achieved by welding, screwing, clamping, bonding and other techniques. The fixing seat 32 and the supporting portion 31 may be separate structures, and the two may also be connected by welding, screwing, clamping, bonding and other techniques. Of course, the fixing seat 32 and the supporting portion 31 may also be formed into an integral structure by an integrated molding process, which can save the assembly process of the fixing seat 32 and the supporting portion 31, and is conducive to improving the structural strength of the supporting protrusion 30 without increasing the cost.

[0086] The fixing seat 32 may be, for example, a rectangular parallelepiped structure, or may also be a prism structure. Figure 7 and Figure 8In the example shown, the fixing seat 32 may be a truncated cone structure or a prism structure. With this design, on the one hand, the upper surface of the fixing seat 32 is a plane, so that the support portion 31 can be stably arranged on the top of the fixing seat 32; on the other hand, the cross-sectional area of ​​the fixing seat 32 in the direction perpendicular to the central axis of the pressure ring 20 gradually decreases from the bottom to the top of the fixing seat 32, so that the volume of the fixing seat 32 is as small as possible, and the heat transferred from the tray 10 to the wafer 200 through the fixing seat 32 and the support portion 31 by heat conduction is as small as possible, thereby improving the temperature uniformity of the surface of the wafer 200.

[0087] In some embodiments, the supporting protrusion 30 is further configured to have a lower thermal conductivity than the tray 10. This embodiment is designed in this way to reduce the amount of heat transferred from the supporting protrusion 30 to the wafer 200, thereby helping to reduce the impact of the contact position between the wafer 200 and the supporting protrusion 30 on the temperature uniformity of the surface of the wafer 200 through heat conduction, and further improve the temperature uniformity of the surface of the wafer 200.

[0088] For example, the material of the supporting protrusion 30 may be different from the material of the tray 10 , and the thermal conductivity of the material of the supporting protrusion 30 is lower than the thermal conductivity of the material of the tray 10 .

[0089] Alternatively, a coating is provided on the outer surface of the support protrusion 30, and the thermal conductivity of the coating is lower than the thermal conductivity of the tray 10. For example, the material of the tray 10 can be graphite, and the material of the coating can be silicon carbide (SiC). In the present embodiment, the material of the tray 10 and the support protrusion 30 can be the same, for example, both are graphite. In this way, the tray 10 and the support protrusion 30 of the same material can be formed into an integral part through an integrated molding process, which eliminates the assembly process of the tray 10 and the support protrusion 30 compared to welding or screwing, and is conducive to improving the structural strength of the tray assembly 100 without increasing the cost.

[0090] Embodiment 2

[0091] The embodiment of the present application provides another tray assembly 100, which is basically the same as the first embodiment, except that, in the embodiment, all the support protrusions 30 are arranged in multiple circles on the upper surface of the tray 10, and the multiple circles of support protrusions 30 are arranged at radial intervals along the tray 10, and the center of each circle of support protrusions 30 is located on the central axis of the pressure ring 20.

[0092] The following is a detailed description taking the example of all the supporting protrusions 30 being arranged in two circles on the upper surface of the tray 10. After reading the technical solution below, those skilled in the art can obviously understand the technical solution of arranging the supporting protrusions 30 in more than three circles on the upper surface of the tray 10.

[0093] Fig. 9This is a schematic diagram of a tray assembly 100 provided in Embodiment 2 of the present application. Fig.10 A top view of a tray assembly 100 provided in the second embodiment of the present application is shown in FIG. Fig.11 This is a schematic diagram of another tray assembly 100 provided in the second embodiment of the present application. Figures 9 to 11 For the convenience of description, the outer circle of the two circles of support protrusions 30 is called the outermost circle support protrusion 30A, and the inner circle of the two circles of support protrusions 30 is called the innermost circle support protrusion 30B.

[0094] It is understandable that the heights of the supporting protrusions 30 of each circle may be the same or different, and this embodiment does not impose any limitation on this.

[0095] In some examples, such as Fig. 9 and Fig.10 As shown, along the radial direction of the tray 10, the height of each circle of supporting protrusions 30 gradually increases from the center of the tray 10 to the edge of the tray 10. Correspondingly, the height H of the outermost circle of supporting protrusions 30A is A Greater than the height H of the innermost support protrusion 30B B .

[0096] By such arrangement, the tray assembly 100 of this embodiment is suitable for the situation that the edge of the wafer 200 is warped upward. When the semiconductor process equipment equipped with the tray assembly 100 is used to perform the epitaxial process, when the temperature of the wafer 200 is room temperature, the wafer 200 is placed on the outermost circle support protrusion 30A, and the innermost circle support protrusion 30B is spaced from the back of the wafer 200 in the vertical direction Z. When the temperature of the wafer 200 is high and thermal stress is generated on the surface of the wafer 200, the edge of the wafer 200 is warped and deformed upward, and the central area of ​​the wafer 200 is concave downward, and the central area of ​​the wafer 200 can then abut against the innermost circle support protrusion 30B. In this way, the contact position of the wafer 200 with the tray assembly 100 increases after the warping deformation occurs, thereby improving the support effect of the tray assembly 100 on the wafer 200, and effectively reducing the risk of displacement or flying of the warped and deformed wafer 200 when the tray assembly 100 rotates.

[0097] In other examples, such as Fig.11 As shown, along the radial direction of the tray 10, the height of each circle of supporting protrusions 30 gradually decreases from the center of the tray 10 to the edge of the tray 10. Correspondingly, the height H of the outermost circle of supporting protrusions 30A is A Smaller than the height H of the innermost support protrusion 30B B .

[0098] By such arrangement, the tray assembly 100 of this embodiment is suitable for the situation that the edge of the wafer 200 is warped downward. When the semiconductor process equipment equipped with the tray assembly 100 is used to perform the epitaxial process, when the temperature of the wafer 200 is room temperature, the wafer 200 is placed on the innermost circle support protrusion 30B, and there is a gap between the outermost circle support protrusion 30A and the back of the wafer 200 in the vertical direction Z. When the temperature of the wafer 200 is high and thermal stress is generated on the surface of the wafer 200, the edge of the wafer 200 is warped and deformed downward, and the central area of ​​the wafer 200 is convex upward, and the distance between the edge area of ​​the wafer 200 and the upper surface of the tray 10 is reduced, and the edge area of ​​the wafer 200 can then abut against the outermost circle support protrusion 30A. In this way, the contact position of the wafer 200 with the tray assembly 100 increases after the warping deformation occurs, thereby improving the support effect of the tray assembly 100 on the wafer 200, and effectively reducing the risk of displacement or flying of the warped and deformed wafer 200 when the tray assembly 100 rotates.

[0099] In any of the above embodiments, the height difference ΔH between two adjacent circles of the supporting protrusions 30 is less than 50 μm. Fig. 9 and Fig.10 In the example shown, ΔH = H A -H B <50μm; Fig.11 In the example shown, ΔH = H B -H A A large amount of experimental data shows that by designing the height difference between two adjacent circles of supporting protrusions 30 to be less than 50 μm, it is helpful to ensure that the wafer 200 can successively abut against each circle of supporting protrusions 30 during the warping deformation process.

[0100] Furthermore, if Fig.10 As shown, along the circumference of the tray 10, the supporting protrusions 30 of two adjacent circles are staggered. In this way, when the wafer 200 is warped, the wafer 200 can not only resist against the supporting protrusions 30 of each circle, but also the force on the wafer 200 is uniform, which effectively reduces the negative impact of uneven force on the warped wafer 200, and can reduce the risk of wafer 200 flying.

[0101] It is understood that the above embodiments are merely exemplary embodiments used to illustrate the principles of the present invention, but the present invention is not limited thereto. For those skilled in the art, various modifications and improvements can be made without departing from the spirit and essence of the present invention, and these modifications and improvements are also considered to be within the scope of protection of the present invention.

Claims

1. A tray assembly, characterized in that: include: Trays and press rings; The pressing ring is pressed onto the tray, the orthographic projection of the pressing ring on the upper surface of the tray overlaps with the circumferential edge area of ​​the upper surface of the tray, and the inner circumferential surface of the pressing ring and the upper surface of the tray together enclose an installation space; A plurality of supporting protrusions are arranged on the upper surface of the tray, all of which are arranged in the installation space, and all of which are arranged in at least one circle on the upper surface of the tray. The center of each circle of the supporting protrusions is located on the central axis of the pressure ring, and at least one circle of the supporting protrusions is used to support the wafer; and each of the supporting protrusions is configured to have an arc surface as the contact surface with the wafer.

2. The tray assembly according to claim 1, characterized in that: The supporting protrusion includes a supporting portion, the supporting portion has the arc surface, and the cross-sectional shape of the supporting portion is circular, semicircular, arc-shaped or elliptical.

3. The tray assembly according to claim 2, characterized in that: The supporting protrusion also includes a fixing seat located below the supporting portion, the bottom of the fixing seat is fixedly connected to the upper surface of the tray, and the top of the fixing seat is fixedly connected to the supporting portion.

4. The tray assembly according to claim 3, characterized in that: The fixing seat is a truncated cone structure or a prism structure; the cross-sectional area of ​​the fixing seat in a direction perpendicular to the central axis of the pressure ring gradually decreases from the bottom to the top of the fixing seat.

5. The tray assembly according to claim 1, characterized in that: The thermal conductivity of the supporting protrusion is lower than the thermal conductivity of the tray.

6. The tray assembly according to claim 5, characterized in that: A coating is disposed on an outer surface of the supporting protrusion, and a thermal conductivity of the coating is lower than a thermal conductivity of the tray.

7. The tray assembly according to claim 1, characterized in that: One circle of the supporting protrusions is used to support the wafer, and a plurality of the supporting protrusions arranged in a circle are distributed at intervals around the central axis of the pressure ring.

8. The tray assembly according to claim 7, characterized in that: All the supporting protrusions are arranged in multiple circles on the upper surface of the tray, and the multiple circles of supporting protrusions are arranged at intervals along the radial direction of the tray; Along the radial direction of the tray, the height of each circle of the supporting protrusions gradually increases from the center of the tray to the edge of the tray, and the supporting protrusions in the outermost circle are used to support the wafer; or, Along the radial direction of the tray, the height of each circle of the supporting protrusions gradually decreases from the center of the tray to the edge of the tray, and the innermost circle of the supporting protrusions is used to support the wafer.

9. The tray assembly according to claim 8, characterized in that: The height difference between two adjacent circles of the supporting protrusions is less than 50 μm; and / or, Two adjacent circles of the supporting protrusions are staggered along the circumferential direction of the pressure ring.

10. A carrying device, characterized in that: include: Pedestal; as well as The tray assembly according to any one of claims 1 to 9, wherein the tray assembly is stacked on the base, and the base is used to support the tray assembly.

11. A semiconductor process equipment, characterized in that: include: Process chamber; as well as The carrier device as claimed in claim 10, wherein the tray assembly of the carrier device is located in the process chamber.

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