Edge ring assembly, thin film growth apparatus, system and method

Abstract

The application discloses an edge ring assembly, a thin film growth reaction cavity and system and a thin film growth method. The edge ring assembly is located in a thin film growth reaction cavity. A tray for supporting a substrate is arranged in the reaction cavity. The edge ring assembly surrounds the periphery of the tray. The edge ring assembly comprises an edge adjusting ring and an edge supporting ring. The edge adjusting ring comprises a plurality of supporting stakes. The edge supporting ring has a plurality of supporting intervals in the circumferential direction. Different height supporting surfaces are arranged in the same supporting interval. The height of the edge adjusting ring can be adjusted when the bottom surface of the supporting stake is in contact with the supporting surfaces with different heights. The application can prolong the maintenance time of the edge ring assembly and improve the use efficiency of the thin film growth reaction cavity.

Description

Technical Field

[0001] This invention relates to the field of semiconductor processing technology, and more particularly to the field of thin film growth reaction technology. Background Technology

[0002] Currently, the process of epitaxial growth to fabricate thin films on substrates is widely used in the manufacturing of integrated circuits and discrete components. The epitaxial growth process is usually carried out in a pressure-controlled reaction chamber. By supplying reaction gases for film growth into the reaction chamber and controlling the temperature, pressure and other conditions of the reaction chamber, the reaction gases can grow qualified thin films on the surface of the substrate.

[0003] The inconsistent airflow distribution between the central and edge regions of the substrate within the reaction chamber leads to inconsistent film quality in different areas, affecting the yield of substrate processing. Currently, an edge ring is often placed around the substrate within the reaction chamber to adjust the airflow at the edges. However, since film growth occurs not only on the substrate surface but also on the upper surface of the edge ring, after processing a certain number of substrates, a thicker film will grow on the upper surface of the edge ring. When the film thickness on the upper surface of the edge ring exceeds a certain value, the edge ring's ability to adjust the airflow changes, resulting in differences in the uniformity of substrate processing between different batches. This is undesirable in industrial production. Summary of the Invention

[0004] To address the aforementioned problems, the present invention provides an edge ring assembly located within a thin film growth reaction chamber. A substrate support tray is disposed within the reaction chamber, and the edge ring assembly is arranged around the periphery of the tray. The edge ring assembly includes an edge adjustment ring and an edge support ring. The edge adjustment ring includes a plurality of support posts. The edge support ring has a plurality of support sections in the circumferential direction, with support surfaces of different heights within the same support section. The bottom surface of each support post contacts the support surfaces of different heights, thereby allowing the edge adjustment ring to have different heights.

[0005] Optionally, the support surface is an inclined surface with an angle along the circumferential direction, and the support surfaces of several support intervals have the same or different angles of inclination.

[0006] Optionally, the support surface includes a plurality of steps arranged along the circumferential direction, and the support surfaces of the plurality of support intervals have the same or different step shapes.

[0007] Optionally, the bottom surface of the support pile matches the shape of the support surface.

[0008] Optionally, the bottom surface of the support pile is an inclined surface, a horizontal surface, or a stepped surface.

[0009] Optionally, the number of support intervals is greater than or equal to the number of support piles, and the number of support piles is greater than or equal to 3.

[0010] Optionally, the edge ring assembly further includes an edge cover ring located above the edge adjustment ring.

[0011] Optionally, the distance between the inner wall of the edge covering ring and the outer side wall of the tray is less than or equal to the distance between the inner wall of the edge adjusting ring and the outer side wall of the tray.

[0012] Optionally, the edge covering ring includes a lower extension that extends downward along the inner wall.

[0013] Furthermore, the present invention also discloses a thin film growth apparatus, including a thin film growth reaction chamber, characterized in that a tray for supporting a substrate is disposed in the reaction chamber, the tray including a central region for supporting the substrate and an edge region extending outward from the central region, and an edge ring assembly is disposed around the periphery of the central region of the tray, the edge ring assembly having the features described above.

[0014] Optionally, the edge region of the tray is used to support the edge ring assembly.

[0015] Optionally, the outer diameter of the edge support ring is greater than or equal to the outer diameter of the edge region of the tray.

[0016] Optionally, the outer diameter of the edge adjusting ring is greater than or equal to the outer diameter of the edge support ring.

[0017] Optionally, the tray and the edge ring assembly may be made of the same or different materials.

[0018] Optionally, the material of the tray and the edge ring assembly is either carbon or silicon carbide.

[0019] Optionally, a rotating device is provided inside the reaction chamber, which drives the tray and the edge ring assembly to rotate.

[0020] Furthermore, the present invention also discloses a thin film growth system, the system including the thin film growth reaction chamber described above and a transfer chamber, wherein a robotic arm is disposed in the transfer chamber, the robotic arm being capable of picking up and placing the edge ring assembly or raising and lowering the edge adjustment ring.

[0021] Optionally, the thin film growth system further includes an adjustment cavity connected to the transmission cavity, wherein a position adjustment device is provided in the adjustment cavity for realizing the relative rotation of the edge adjustment ring and the edge support ring.

[0022] Furthermore, the present invention also discloses a thin film growth method, comprising the following steps:

[0023] Place the substrate on the tray inside the thin film growth reaction chamber as described above;

[0024] Thin film growth gas is supplied into the reaction chamber, and the temperature inside the reaction chamber is controlled so that the required thin film can grow on the surface of the substrate.

[0025] The positional relationship between the surface of the edge ring assembly after the thin film is deposited and the surface of the substrate is monitored. When the positional relationship exceeds a certain threshold, the relative positions of the edge adjustment ring and the edge support ring are adjusted so that the support pile contacts the support surface at different heights, thereby realizing the positional adjustment of the upper surface of the edge ring assembly and the upper surface of the substrate.

[0026] Furthermore, the edge adjustment ring is raised and the edge support ring is rotated, so that the area opposite the support pile of the edge support ring and the edge adjustment ring is switched to a support surface with a lower height.

[0027] Optionally, the edge ring assembly is moved out of the reaction chamber, and the relative positions of the edge adjustment ring and the edge support ring are adjusted so that the area opposite the support pile of the edge support ring and the edge adjustment ring is switched to a support surface with a lower height. The adjusted edge ring assembly is then moved into the reaction chamber.

[0028] Optionally, the method for adjusting the relative position of the edge adjusting ring and the edge support ring is mechanical adjustment or manual adjustment.

[0029] The edge ring assembly disclosed in this invention can adjust the height of its upper surface by adjusting the relative positions of the edge adjustment ring and the edge support ring, thereby compensating for the increase in the height of the upper surface of the edge ring assembly caused by the continuous increase in the thickness of the thin film layer deposited on the upper surface. The technical solution of this invention can significantly reduce the number of times the edge ring assembly needs to be removed from the reaction chamber, improving the working efficiency of the reaction chamber while reducing the cost of maintaining the workpiece within the reaction chamber. Attached Figure Description

[0030] Figure 1 A schematic diagram of a thin film growth reaction chamber is shown.

[0031] Figure 2 For along Figure 1 A schematic diagram of the cross-section along the AA direction;

[0032] Figures 3A-3C For along Figure 1 Schematic diagram of the cross section in the BB direction;

[0033] Figure 4 A schematic diagram of a thin film growth system is shown.

[0034] Figure 5A and Figure 5B For another embodiment along Figure 1 Schematic diagram of the cross section in the BB direction;

[0035] Figure 6A and Figure 6B For another embodiment along Figure 1 Schematic diagram of the cross section in the middle BB direction; Detailed Implementation

[0036] like Figure 1 As shown, this invention discloses a thin film growth apparatus, which includes a reaction chamber 100, a tray 10 supporting a substrate W disposed within the reaction chamber, a rotating device 50 disposed below the tray 10, the rotating device 50 driving the tray to rotate, and an air inlet device 80 disposed above the reaction chamber 100 for supplying process gas into the reaction chamber. The process gas achieves uniform thin film growth on the rotating substrate surface. The tray 10 includes a central region supporting the substrate and an edge region 101 surrounding the central region, wherein the upper surface of the edge region is lower than the upper surface of the central region. In one embodiment, an edge ring assembly is disposed around the tray 10, located on the upper surface of the edge region 101, and the edge ring assembly includes an edge adjustment ring 13 and an edge support ring 11. The edge adjustment ring includes an adjustment ring body 13a and a plurality of support piles 13b. The edge support ring 11 has a plurality of support sections 110 in the circumferential direction. Within the same support section, there are support surfaces 11s of different heights. The edge adjustment ring 13 and the edge support ring 11 can rotate relative to each other. When the two rotate relative to each other, the bottom surface of the support pile contacts the support surfaces of different heights, and the edge adjustment ring has different heights.

[0037] Before the thin film growth process begins, a substrate is placed on a tray 10 inside the thin film growth reaction chamber. Thin film growth gas is supplied to the reaction chamber, and the temperature within the chamber is controlled to allow the desired thin film to grow on the substrate surface. During the process, in addition to growing on the substrate surface, the thin film also grows on the surface of the edge ring assembly. After several batches of substrate processing, the thickness of the film deposited on the edge ring assembly surface exceeds a certain range, causing a significant change in the position of the upper surface of the edge ring assembly relative to the substrate surface. This affects the airflow distribution in the substrate edge region, resulting in poor uniformity of substrate processing between different batches. To solve this problem, the present invention needs to monitor the positional relationship between the surface of the edge ring assembly after film deposition and the upper surface of the substrate. When this positional relationship exceeds a certain threshold, the relative positions of the edge adjustment ring and the edge support ring need to be adjusted so that the support post contacts the lower-height support surface, thereby lowering the position of the edge adjustment ring 13 and adjusting the position of the upper surface of the edge ring assembly relative to the upper surface of the substrate to a reasonable range.

[0038] Figure 2 For along Figure 1 The cross-sectional schematic diagram in the AA direction shows that the edge support ring is provided with several support sections 110 along the circumferential direction. Each support section has a support surface 11s with different heights. The shaded part in the figure is the projection of the support pile 13b of the edge adjustment ring on the support surface 11s. Figures 3A-3C For along Figure 1 A schematic diagram of the cross-section along the BB direction. Based on... Figure 3A As shown in the schematic diagram, the support surface 11s is an inclined plane with a tilt angle, and the support surface within each support section has a height variation trend along the circumference from a high point 11t to a low point 11b. The support pile 13b has a bottom surface 13s that matches the support surface. Figure 3A In the illustrated embodiment, the bottom surface of the support pile is an inclined surface with the same inclination angle as the support surface 11s. In other embodiments, the bottom surface of the support pile may have other shapes. Optionally, the edge adjustment ring 13 includes three or more support piles. Therefore, even if the bottom surface of the support pile has different inclination angles from the support surface, three or more support piles can stably support the edge adjustment ring. To ensure stable support for the edge adjustment ring, the number of support intervals must be greater than or equal to the number of support piles. The shape of the support surface in different support intervals may be the same or different.

[0039] In one embodiment, the edge ring assembly further includes an edge cover ring 15 located above the edge adjustment ring. The upper surface of the edge cover ring is approximately level with the substrate height. In another embodiment, the edge cover ring may be omitted, in which case the upper surface of the edge adjustment ring is approximately level with the substrate height.

[0040] Figure 3A A cross-sectional schematic diagram showing the edge ring assembly in its initial state, at which time the surface of the edge covering ring 15 has not been deposited with a thin film material, such as Figure 3B shown. After processing several batches of substrates in the reaction chamber, a thin film layer 16 of a certain thickness will grow on the surface of the edge covering ring. When it is known from monitoring the thickness of the thin film layer or through calculation that the height of the upper surface of the edge ring assembly exceeds the height of the substrate surface by too much, which may affect the processing results of different batches of substrates, it is necessary to adjust the height of the edge adjustment ring.

[0041] Figure 3B and Figure 3C respectively show the adjustment states of the edge ring assembly when the thin film layer is at two thicknesses. When the edge ring assembly is just set in the reaction chamber, no thin film layer is deposited on the surface of the edge ring assembly. At this time, the support pile of the edge adjustment ring contacts the support surface at the higher position of the edge support ring, such as Figure 3A the support surface near 11t in. At this time, the distance between the lower surface of the edge adjustment ring 13a and the upper surface of the edge area of the tray is H1, and the gap between the edge adjustment ring 13a and the edge support ring 13b is 31. As the substrate processing process in the reaction chamber continues, the thin film layer on the edge ring assembly grows from nothing to something and from thin to thick. When the thickness of the thin film layer exceeds a certain threshold, the relative positions of the edge adjustment ring and the edge support ring are adjusted so that the support pile of the edge adjustment ring contacts the support surface at the lower position of the edge support ring. At this time, the distance between the lower surface of the edge adjustment ring 13a and the upper surface of the edge area of the tray is H2, H2 < H1, and the gap between the edge adjustment ring 13a and the edge support ring 13b is 31'. By reducing the position of the edge adjustment ring, compensation for the thickness of the thin film layer is achieved. Even if a thin film layer of a certain thickness has grown on the edge ring assembly, the height difference between the height of this thin film layer and the height of the substrate surface is approximately the same as the height difference between the edge ring assembly and the substrate surface in the initial state, and the edge ring assembly can continue to work without affecting the uniformity of different batches of substrates.

[0042] When the edge ring assembly continues to work for a period of time, the thickness of the thin film layer 16' continues to increase. At this time, it is necessary to adjust the edge ring assembly again, further adjust the relative positions of the edge adjustment ring and the edge support ring so that the support pile of the edge adjustment ring contacts the support surface at an even lower position of the edge support ring, such as near the support surface 11b. At this time, the position of the edge ring assembly drops further to offset the height increase caused by the increase in the thickness of the thin film layer. At this time, the distance between the lower surface of the edge adjustment ring 13a and the upper surface of the edge area of the tray is H3, H3 < H2 < H1, and the gap between the edge adjustment ring 13a and the edge support ring 13b is 31". The gap 31" < gap 31' < gap 31.

[0043] During the height adjustment of the edge adjustment ring, the thermal conductivity between the edge adjustment ring and the edge support ring remains unchanged because the contact area between the support pile and the support surface remains constant. This ensures temperature uniformity within the reaction chamber during the processing of different batches of substrates.

[0044] When the bottom surface of the support pile contacts the lowest support surface, the edge adjustment ring can no longer descend. At this point, the edge ring assembly needs to be removed, and the thin film layer needs to be removed by external force. After removing the thin film layer, the edge ring assembly returns to its initial state and can be placed back into the reaction chamber to continue working. The height adjustment method is the same as described above, enabling the edge ring assembly to be reused.

[0045] The edge ring assembly disclosed in this invention can adjust the height of its upper surface by adjusting the relative positions of the edge adjustment ring and the edge support ring, thereby compensating for the increase in the height of the upper surface of the edge ring assembly caused by the continuous increase in the thickness of the thin film layer deposited on the upper surface. The technical solution of this invention can significantly reduce the number of times the edge ring assembly needs to be removed from the reaction chamber, improving the working efficiency of the reaction chamber while reducing the cost of maintaining the workpiece within the reaction chamber.

[0046] In the technical solution disclosed in this invention, the relative position adjustment of the edge adjustment ring and the edge support ring can be performed within the reaction chamber, according to... Figure 1 As shown, the tray 10 includes a central region supporting the substrate and an edge region 101 surrounding the central region. The upper surface of the edge region is lower than the upper surface of the central region. In one embodiment, an edge ring assembly is located on the upper surface of the edge region. When the rotating device 50 below the tray rotates the tray, the edge ring assembly rotates synchronously with the tray. When it is necessary to adjust the relative position of the edge adjustment ring and the edge support ring, a robotic arm outside the reaction chamber can be used to raise the edge adjustment ring, and then the rotating device 50 can be used to rotate the edge support ring by a certain angle. When the edge adjustment ring is lowered, the contact area between the support pile and the support surface changes. The height of the edge adjustment ring can be easily adjusted using the robotic arm and the rotating device.

[0047] Figure 4 A thin film growth system is shown, comprising at least one thin film growth reaction chamber 100 and a transfer chamber 150. A robotic arm 155 is disposed within the transfer chamber 150, and the robotic arm can raise and lower an edge adjustment ring. To enable the robotic arm to raise and lower the edge adjustment ring, the height of the support pile can be set to ensure that the gap 31 between the edge adjustment ring and the edge support ring can accommodate the robotic arm, or the outer diameter of the edge adjustment ring can be set to be larger than the outer diameter of the edge support ring. In another embodiment, a space to accommodate the robotic arm can also be provided inside the sidewall of the edge adjustment ring. Specific designs can be made according to the shape and size of the robotic arm, which will not be elaborated here.

[0048] In another embodiment, the height adjustment of the edge ring assembly can also be performed outside the reaction chamber. In this case, a robotic arm inside the transfer chamber moves the edge ring assembly entirely out of the reaction chamber. In this embodiment, the thin film growth system can be equipped with an adjustment chamber 120, within which a position adjustment device 122 is installed to achieve relative rotation between the edge adjustment ring and the edge support ring. After the height of the edge ring assembly is adjusted, the robotic arm moves it entirely into the reaction chamber for processing. To enable the robotic arm to handle the edge ring assembly as a whole, the outer diameter of the edge support ring can be set to be greater than or equal to the outer diameter of the tray edge area.

[0049] Figure 5A and Figure 5B A schematic diagram of an edge ring assembly according to another embodiment is shown. In this embodiment, the support surface of each support section includes several steps arranged along the circumferential direction, and the bottom surface of the support pile matches the shape of the support surface. Figure 5A In one embodiment, the bottom surface of the support pile is a stepped surface that matches the stepped support surface. When the edge support ring rotates relative to the edge adjustment ring, the bottom surface of the support pile contacts stepped surfaces of different heights, thereby adjusting the height of the edge adjustment ring. Figure 5B In this embodiment, the bottom surface of the support pile is a planar structure. When the edge support ring rotates relative to the edge adjustment ring, the bottom surface of the support pile contacts a step surface at a certain height, thereby adjusting the height of the edge adjustment ring. The support surfaces of several support sections have the same or different step morphologies. As long as the bottom surfaces of several support piles are in contact with support surfaces at the same height, stable support for the edge adjustment ring can be achieved. As described above, adjusting the relative positions of the edge support ring and the edge adjustment ring allows the support pile to contact steps at different heights, thereby adjusting the height of the upper surface of the edge adjustment ring.

[0050] An edge covering ring 15 can be disposed above the edge adjustment ring of the present invention. The material of the edge covering ring can be the same as that of the tray to improve the uniformity of film growth in the edge and center regions of the substrate. In the present invention, the film grown in the reaction chamber can be silicon carbide, therefore the material of the edge covering ring 15 can be silicon carbide. In another embodiment, the material of the edge covering ring can be carbon or other materials that can withstand the higher temperatures in the reaction chamber. The edge covering ring and the edge adjustment ring can be two components; in other embodiments, they can be a single component, depending on the specific requirements. When the film grown in the reaction chamber is silicon carbide, since the film growth process requires high temperatures, the edge ring assembly needs to be able to withstand the temperature of silicon carbide growth, for example, exceeding 1000°C.

[0051] The thin film growth process generates a large amount of deposited impurities. To prevent these impurities from entering the edge ring assembly, which could cause instability in the support between the edge adjustment ring and the edge support ring, and increase the difficulty of cleaning, further measures must be taken. Figure 6A and Figure 6B Schematic diagrams of two embodiments of the edge ring assembly are shown, wherein the distance between the inner wall of the edge cover ring 15 and the outer sidewall of the tray is less than or equal to the distance between the inner wall of the edge adjustment ring and the outer sidewall of the tray. This allows the edge cover ring to block deposited impurities, preventing them from entering the gap between the edge adjustment ring and the edge support ring. Figure 6B In the illustrated embodiment, the edge covering ring includes a lower extension 15a extending downward along the inner wall. Its function is similar to... Figure 6A The two serve the same purpose: to reduce the entry of sediment impurities into the gap between the edge adjustment ring and the edge support ring.

[0052] It should be noted that, in the embodiments of the present invention, the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing the embodiments. They do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0053] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0054] Although the present invention has been described in detail through the preferred embodiments above, it should be understood that the above description should not be considered as a limitation of the present invention. Various modifications and substitutions to the present invention will be apparent to those skilled in the art after reading the above description. Therefore, the scope of protection of the present invention should be defined by the appended claims.

Claims

1. A thin film growth apparatus, comprising a thin film growth reaction chamber, characterized in that, A tray supporting the substrate is disposed inside the reaction chamber. The tray includes a central region for supporting the substrate and an edge region extending outward from the central region. An edge ring assembly is disposed around the periphery of the substrate. The edge ring assembly includes an edge adjustment ring and an edge support ring. The edge adjustment ring includes a plurality of support piles; The edge support ring has several support sections in the circumferential direction, and support surfaces of different heights are provided in the same support section; The bottom surface of the support pile contacts the support surface at different heights, so that the edge adjustment ring has different heights; A rotating device is installed inside the reaction chamber, which drives the tray and the edge ring assembly to rotate.

2. The thin film growth apparatus as described in claim 1, characterized in that, The edge region of the tray is used to support the edge ring assembly.

3. The thin film growth apparatus as described in claim 1, characterized in that, The outer diameter of the edge support ring is greater than or equal to the outer diameter of the edge region of the tray.

4. The thin film growth apparatus as described in claim 1, characterized in that, The outer diameter of the edge adjustment ring is greater than or equal to the outer diameter of the edge support ring.

5. The thin film growth apparatus as described in claim 1, characterized in that, The tray and the edge ring assembly may be made of the same or different materials.

6. The thin film growth apparatus as described in claim 1, characterized in that, The tray and the edge ring assembly are made of either carbon or silicon carbide.

7. A thin film growth system, characterized in that, The system includes at least one thin film growth apparatus as described in any one of claims 1-6 and a transfer cavity, wherein a robotic arm is disposed in the transfer cavity, and the robotic arm can pick up and place the edge ring assembly or raise and lower the edge adjustment ring.

8. The thin film growth system as described in claim 7, characterized in that, The thin film growth system further includes an adjustment cavity connected to the transmission cavity, and a position adjustment device is provided in the adjustment cavity to realize the relative rotation of the edge adjustment ring and the edge support ring.

9. A method for growing a thin film, comprising the following steps: A substrate is placed on a tray within the thin film growth apparatus as described in any one of claims 1-6 or the thin film growth system as described in any one of claims 7-8; Thin film growth gas is supplied into the reaction chamber, and the temperature inside the reaction chamber is controlled so that the required thin film can grow on the surface of the substrate. The positional relationship between the surface of the edge ring assembly after the thin film is deposited and the surface of the substrate is monitored. When the height difference exceeds a certain threshold, the relative positions of the edge adjustment ring and the edge support ring are adjusted so that the support pile contacts the support surface at different heights, thereby adjusting the height of the upper surface of the edge ring assembly.

10. The method as described in claim 9, characterized in that, Raise the edge adjustment ring and rotate the edge support ring so that the area opposite the support pile of the edge support ring and the edge adjustment ring is switched to a support surface with a lower height.

11. The method as described in claim 9, characterized in that, The edge ring assembly is moved out of the reaction chamber, and the relative positions of the edge adjustment ring and the edge support ring are adjusted so that the area opposite the support pile of the edge support ring and the edge adjustment ring is switched to a support surface with a lower height. The adjusted edge ring assembly is then moved into the reaction chamber.

12. The method as described in claim 11, characterized in that, The method for adjusting the relative position of the edge adjusting ring and the edge support ring is mechanical adjustment or manual adjustment.

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