Mounting table and film forming apparatus

Abstract

Provided is a mounting table for rotating a substrate in a vapor phase growth device, the mounting table including a recessed part in which the substrate is accommodated, a ring part provided around the recessed part, and a plurality of first protruding parts provided so as to protrude upward from an upper face of the ring part, the plurality of first protruding parts preventing the substrate from being cast out due to centrifugal force applied to the substrate during rotation, and having a shape for regulating the flow of gas that is fed thereto.

Description

Stage and Film Deposition Apparatus

[0001] The present disclosure relates to a stage and a film deposition apparatus.

[0002] In Patent Document 1, a substrate placed on a support table is accommodated in a chamber, and a vapor growth apparatus is disclosed in which a first flow path for supplying a gas for film formation and a second flow path for exhausting the gas are connected to the chamber. Patent Document 1 discloses that the support table is provided with a plurality of first convex portions arranged so as to surround the substrate and restraining movement of the substrate in a substantially horizontal direction in the same direction as the substrate surface with respect to the substrate.

[0003] Japanese Patent Application Laid-Open No. 2009-267422

[0004] The present disclosure provides a technique for preventing the substrate from jumping out while not inhibiting the flow of the material gas.

[0005] According to one aspect of the present disclosure, there is provided a stage for rotating a substrate of a vapor growth apparatus, including a recess in which the substrate is accommodated, a ring portion provided around the recess, and a plurality of first convex portions provided so as to protrude upward from the upper surface of the ring portion and having a shape that prevents the substrate from jumping out due to the centrifugal force applied to the substrate during rotation and rectifies the gas to be fed.

[0006] The present disclosure provides a technique for preventing the substrate from jumping out while not inhibiting the flow of the material gas.

[0007] FIG. 1 is a diagram for explaining the configuration of a film deposition apparatus according to the present embodiment. FIG. 2 is a perspective view of a stage in the film deposition apparatus according to the present embodiment. FIG. 3 is a plan view of a stage in the film deposition apparatus according to the present embodiment. FIG. 4 is a diagram for explaining the shape of a first convex portion of a stage in the film deposition apparatus according to the present embodiment. FIG. 5 is a diagram for explaining the gas flow near a first convex portion of a stage in the film deposition apparatus according to the present embodiment. FIG. 6 is a diagram for explaining the gas flow near a first convex portion of a stage in a film deposition apparatus of a reference example.

[0008] Hereinafter, embodiments for carrying out this disclosure will be described with reference to the drawings. In this specification and the drawings, substantially identical components are denoted by the same reference numerals to avoid redundant explanations. For ease of understanding, the scale of the parts in the drawings may differ from that of the actual parts. In directions such as parallel, right angles, orthogonal, horizontal, vertical, up and down, and left and right, deviations are permitted to the extent that they do not impair the effect of the embodiment. The shape of the corners is not limited to right angles and may be rounded. Parallel, right angles, orthogonal, horizontal, and vertical may include substantially parallel, substantially right angles, substantially orthogonal, substantially horizontal, and substantially vertical.

[0009] The film deposition apparatus according to this embodiment will now be described. Figure 1 is a diagram illustrating the configuration of a film deposition apparatus 1, which is an example of a film deposition apparatus according to this embodiment.

[0010] The film deposition apparatus 1 performs a single-wafer film deposition process by injecting a material gas onto the surface of the substrate while rotating the substrate. The film deposition apparatus 1 is a so-called vapor phase growth apparatus. The film deposition apparatus 1 comprises a chamber 10, a mounting table 20, a rotating stage 30, a substrate heater 40, and a gas injector 50.

[0011] Chamber 10 is used to process the substrate W, with the substrate W placed inside. Inside the chamber 10 are a mounting table 20, a rotating stage 30, and a substrate heater 40. A gas injector 50 is also located at the top of the chamber 10.

[0012] The chamber 10 is exhausted by gas from the gas exhaust port 10e. Due to the exhaust of gas from the gas exhaust port 10e, the inside of the chamber 10 is under reduced pressure during the film formation process.

[0013] The mounting base 20 holds the substrate W. The mounting base 20 is a so-called susceptor. Details of the mounting base 20 will be described later.

[0014] The rotating stage 30 rotates the mounting table 20 along the direction indicated by arrow A. As the rotating stage 30 rotates the mounting table 20, the substrate W held by the mounting table 20 rotates.

[0015] The substrate heater 40 heats the mounting table 20. As the substrate heater 40 heats the mounting table 20, the substrate W held by the mounting table 20 is heated.

[0016] The gas injector 50 supplies material gas into the chamber 10, as shown by arrow S. A portion of the supplied material gas deposits on the substrate W, thereby creating a film on the substrate W made of the material contained in the material gas.

[0017] A portion of the material gas is exhausted from the gas exhaust port 10e, as shown by arrow E.

[0018] In the film deposition apparatus 1, the substrate W is placed on the mounting table 20 and rotated by the rotating stage 30. While the substrate W is rotating, the film deposition apparatus 1 flows material gas from the gas injector 50 in a direction perpendicular to the surface of the substrate W to perform the film deposition process.

[0019] Since the substrate W is rotating, the material gas supplied to the surface of the substrate W flows outwards from the substrate W, creating vortices in the same direction as the rotation.

[0020] Next, the mounting table in the film deposition apparatus according to this embodiment will be described. Figure 2 is a perspective view of the mounting table 20 in the film deposition apparatus 1, which is an example of the film deposition apparatus according to this embodiment. Figure 3 is a plan view of the mounting table 20 in the film deposition apparatus 1, which is an example of the film deposition apparatus according to this embodiment.

[0021] The mounting base 20 includes a recess 21 in which the substrate W is housed, and a ring portion 22 provided around the recess 21. The mounting base 20 also includes a plurality of first protrusions 23 that project upward from the upper surface 22S of the ring portion 22.

[0022] As described above, the substrate W rotates during the film deposition process in the film deposition apparatus 1. When the substrate W rotates, the centrifugal force generated by the rotation may cause the substrate W to fly off the mounting table 20. Therefore, in order to prevent the substrate W from flying off due to the centrifugal force acting on the substrate W during rotation, the film deposition apparatus 1 is provided with a first protrusion 23 on the ring portion 22. Details of the first protrusion 23 will be described later.

[0023] The mounting base 20 includes a second protrusion 24 that protrudes upward from the lower surface 21S of the recess 21 in order to place the substrate W in the recess 21. The second protrusion 24 has an opening 24a that becomes open when the substrate W is placed on it. In other words, the second protrusion 24 has a C-shape with a part cut out, rather than being circular in plan view.

[0024] For example, if the second protrusion 24 is circular in plan view, when the substrate W is placed on it, gas may not escape from the space formed by the lower surface 21S, the substrate W, and the second protrusion 24 when the film deposition apparatus 1 reduces the pressure inside the chamber 10. Therefore, the second protrusion 24 has a C-shape in plan view so that gas can escape from the opening 24a. In other words, the second protrusion 24 has an opening 24a through which gas passes from the inside of the second protrusion 24. By passing the gas through the opening 24a, the gas in the space formed inside the second protrusion 24 can be escaped. By allowing gas to escape from the opening 24a, the space formed by the lower surface 21S, the substrate W, and the second protrusion 24 can be reduced in pressure more quickly when the film deposition apparatus 1 reduces the pressure inside the chamber 10.

[0025] The shape of the second protrusion 24 is not limited to an annular shape when viewed from above, as shown in Figure 3. For example, it may be an elliptical annular shape, or a polygonal shape such as a triangle or quadrilateral.

[0026] Next, the shape of the first protrusion 23 will be described. Figure 4 is a diagram illustrating the shape of the first protrusion 23 of the mounting table 20 in a film deposition apparatus 1, which is an example of a film deposition apparatus according to this embodiment.

[0027] The first protrusion 23 has a shape that rectifies the flow of the material gas being supplied, in other words, a shape that does not obstruct the flow of the material gas, a so-called streamlined shape. That is, the first protrusion 23 is streamlined with respect to the direction of the material gas flow. The first protrusion 23 is provided such that its longitudinal direction LD is in the material gas flow direction GS. For example, the first protrusion 23 has an elliptical shape when viewed from above.

[0028] The first protrusion 23 is narrower in width with respect to the material gas flow direction GS. Specifically, the width of the first protrusion 23 as viewed from the material gas flow direction GS between side surfaces 23S1 and 23S2, which are the sides aligned with the material gas flow direction GS, is narrower than the width aligned with the material gas flow direction GS. In other words, the width D2 of the first protrusion 23 in the short direction is shorter than the length D1 of the first protrusion 23 in the longitudinal direction LD.

[0029] Furthermore, each of the side surfaces 23S1 and 23S2 is inclined with respect to the rotational direction R. That is, the first protrusion 23 has a surface that is inclined with respect to the rotational direction R. For example, the longitudinal direction LD of the first protrusion 23 is inclined at an angle θ1 (in degrees) with respect to the radial line AX. Since the rotational direction is the transverse direction in Figure 4 along line AX, the longitudinal direction LD of the first protrusion 23 is inclined with respect to the rotational direction R by 90 degrees minus an angle θ1 along line AX. The angle θ1 is approximately equal to the angle between the material gas flow direction GS and line AX. The angle θ1 may be appropriately determined between 50 and 80 degrees, for example, taking into consideration the material gas flow direction GS. The angle θ1 is, for example, 50 degrees, 60 degrees, 70 degrees, or 80 degrees.

[0030] Furthermore, the leading corner 23a of the first protrusion 23 in the rotational direction R is chamfered with an R-chamfer. The dimension of the R-chamfer at corner 23a is a radius of 2 mm (R2) or less. In other words, the leading corner 23a of the first protrusion 23 is formed sharply. By chamfering corner 23a with an R-chamfer, it is possible to prevent obstruction of the material gas flow.

[0031] Furthermore, the first protrusion 23 is designed to prevent the substrate W from flying off the mounting base 20. The substrate W is housed in the recess 21, and if it is about to fly off, the edge of the substrate W will come into contact with the surface 23C. The surface 23C is formed continuously with the contact surface 21C that contacts the substrate W in the recess 21.

[0032] Furthermore, the contact surface 21C in the recess 21 that contacts the substrate W is provided so as to protrude inward along the radial direction from the side surface 21B that forms the recess 21.

[0033] The upper surface 23T of the first protrusion 23 is positioned higher than the upper surface 22S of the ring portion 22. The edges forming the upper surface 23T of the first protrusion 23 may be chamfered. Chamfering helps to further obstruct the flow of material gas.

[0034] The first protrusion 23 has a shape that rectifies the flow of the material gas being supplied, a so-called streamlined shape, so the film deposition apparatus 1 can prevent the substrate W from flying out while not obstructing the flow of the material gas.

[0035] Next, we will explain the flow of the material gas when the material gas flows near the first protrusion. Figure 5 is a diagram illustrating the gas flow near the first protrusion 23 of the mounting table 20 in a film deposition apparatus 1, which is an example of a film deposition apparatus according to this embodiment. In Figure 5, the flow of the material gas near the first protrusion 23 is indicated by arrows.

[0036] Furthermore, for comparison, Figure 6 shows the gas flow near the protrusion 23z of the mounting platform in the reference example film deposition apparatus. The protrusion 23z of the mounting platform in the reference example film deposition apparatus has a columnar shape with a semicircular cross-section.

[0037] Near the first protrusion 23 in Figure 5, the turbulence of the material gas flow is smaller than the turbulence of the material gas flow at the protrusion 23z of the mounting stage in the reference example film deposition apparatus in Figure 6. The material gas flow is greatly disturbed by the protrusion 23z of the mounting stage in the reference example film deposition apparatus in Figure 6. In particular, the material gas is greatly disturbed in the direction perpendicular to the substrate W. On the other hand, the turbulence of the material gas flow is suppressed near the first protrusion 23.

[0038] In Figures 2 and 3, the mounting table 20 is provided with six first protrusions 23, but the number of first protrusions on the mounting table in the film deposition apparatus according to this embodiment is not limited to six. For example, the mounting table in the film deposition apparatus according to this embodiment may have two or more first protrusions. From the viewpoint of preventing the substrate W from flying out in two directions, it is preferable to have three or more first protrusions on the mounting table in the film deposition apparatus according to this embodiment.

[0039] The first protrusion has a shape that rectifies the flow of the material gas being supplied, so that the film deposition apparatus according to this embodiment can prevent the substrate W from flying out without obstructing the flow of the material gas. By rectifying the flow of the material gas without obstructing it, the film deposition apparatus according to this embodiment can prevent the gas concentration from becoming non-uniform near the first protrusion. By preventing the gas concentration from becoming non-uniform near the first protrusion, it is possible to prevent the film deposited near the first protrusion from becoming non-uniform. In other words, the film deposition apparatus according to this embodiment can suppress turbulence in the flow near the first protrusion, improve the non-uniformity of the gas concentration near the first protrusion, and improve the uniformity of film deposition near the first protrusion.

[0040] The mounting stage and film deposition apparatus according to the present embodiment disclosed herein should be considered in all respects as illustrative and not restrictive. The above embodiments can be modified and improved in various ways without departing from the scope and spirit of the appended claims. The matters described in the above embodiments can be otherwise configured and combined in a non-consistent manner.

[0041] This application claims priority to Basic Patent Application No. 2024-228208, filed with the Japan Patent Office on December 25, 2024, the entire contents of which are incorporated herein by reference.

[0042] 1 Film deposition apparatus 10 Chamber 10e Gas exhaust port 20 Mounting stage 21 Recess 21S Bottom surface 22 Ring portion 22S Top surface 23 First protrusion 23a Corner 23S1, 23S2 Side surface 24 Second protrusion 24a Opening 30 Rotating stage 40 Substrate heater 50 Gas injector

Claims

1. A mounting table for rotating a substrate of a vapor phase growth apparatus, comprising: a recess in which the substrate is housed; a ring portion provided around the recess; and a plurality of first protrusions provided projecting upward from the upper surface of the ring portion, having a shape that prevents the substrate from flying out due to the centrifugal force acting on the substrate during rotation and rectifies the flow of the supplied gas.

2. The mounting platform according to claim 1, wherein the first protrusion is streamlined.

3. The mounting platform according to claim 2, wherein the first protrusion is formed to have a sharp angle in the direction of rotation.

4. The mounting base according to claim 2, wherein the first protrusion has a surface inclined with respect to the direction of rotation.

5. The mounting base according to claim 1, wherein the upper surface of the first protrusion is located higher than the upper surface of the ring portion.

6. The mounting base according to claim 1, wherein the first protrusion has a surface that is formed in the recess and is continuous with a contact surface that protrudes inward and contacts the substrate.

7. The mounting base according to claim 1, comprising a second protrusion projecting upward from the lower surface of the recess and on which the substrate is placed, wherein the second protrusion is annular or polygonal in shape when viewed from above, and the second protrusion has an opening through which gas passes from the inside of the second protrusion.

8. A film deposition apparatus comprising a mounting stage according to any one of claims 1 to 7.

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