Susceptors, CVD equipment

Abstract

To provide a susceptor capable of making the temperature of a wafer uniform in a wafer plane, and CVD equipment including the same.SOLUTION: There is provided a susceptor to hold a wafer in CVD equipment that forms a film on one face side of a discoid wafer by chemical vapor growth. The susceptor includes a first susceptor and a second susceptor arranged to surround around the first susceptor. In the first susceptor, there is formed a first protrusion in contact with at least three or more places of the outer peripheral edges of the wafer on the other face side. In the second susceptor, there is formed a second protrusion in contact with at least three or more places spaced from the first protrusion, of the outer peripheral edges of the wafer on the other face side.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a susceptor for supporting a wafer, and a CVD apparatus. [Background technology]

[0002] Silicon carbide (SiC) has properties such as a dielectric breakdown field one order of magnitude larger than that of silicon (Si), a band gap three times larger, and a thermal conductivity about three times higher. Because of these properties, silicon carbide is expected to be applied to power devices, high-frequency devices, high-temperature operating devices, etc. For this reason, SiC epitaxial wafers have come to be used in the above-mentioned semiconductor devices in recent years.

[0003] SiC epitaxial wafers are manufactured by growing a SiC epitaxial film, which will become the active region of a SiC semiconductor device, on a SiC substrate (SiC wafer).SiC wafers are obtained by processing bulk single crystals of SiC produced by sublimation method, etc., and the SiC epitaxial film is formed using a chemical vapor deposition (CVD) device.

[0004] One example of such a CVD device is one that has a susceptor that rotates around a rotation axis. The rotation of the wafer placed on the susceptor makes the gas supply state in the in-plane direction uniform, allowing a uniform epitaxial film to grow on the SiC substrate. The wafer is transported into the CVD device using a manual or automatic transport mechanism and placed on the susceptor. The susceptor on which the wafer is placed is heated from the back side, and reactive gas is supplied from above to the wafer surface to form a film.

[0005] A known susceptor has a structure in which an inner susceptor and an outer susceptor are separated (see, for example, Patent Document 1). The susceptor shown in Patent Document 1 is composed of an inner susceptor that is smaller than the diameter of the wafer and has a protrusion on its surface for placing the wafer thereon, and an outer susceptor that has an opening in the center and can accommodate the inner susceptor in the opening. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2009-70915 A Summary of the Invention [Problem to be solved by the invention]

[0007] In order to deposit a smooth film of uniform thickness using a film deposition device (CVD device), it is important to keep the temperature uniform across one surface (growth surface) of the wafer during deposition. If the temperature across the wafer is not uniform, there are concerns that the thickness and doping concentration of the deposited film will be non-uniform, that the wafer will be subjected to stress, causing it to warp more, or that the wafer will be subjected to stress, resulting in the generation of new crystal defects such as dislocations.

[0008] However, in the case of a susceptor such as that shown in Patent Document 1, the inner susceptor and the outer susceptor tend to have different temperatures, which tends to cause the temperature of the wafer to become non-uniform. This temperature non-uniformity leads to problems such as non-uniform distribution of the film thickness and doping concentration, worsening wafer warpage, and an increase in crystal defects.

[0009] The present invention has been made in consideration of the above circumstances, and has an object to provide a susceptor capable of making the temperature of a wafer uniform across its surface, and a CVD apparatus including the susceptor. [Means for solving the problem]

[0010] In order to solve the above problems, the present invention proposes the following means. That is, the susceptor of the present invention is a susceptor for holding a wafer in a CVD apparatus for forming a film on one side of a disk-shaped wafer by chemical vapor deposition, the susceptor being composed of a first susceptor and a second susceptor disposed so as to surround the first susceptor,A first projection is formed, and the top of the first projection is The wafer is connected at least at three or more points on the outer periphery of the other side of the wafer. It is possible to The second susceptor has A second protrusion is formed, and the peripheral surface of the second protrusion 24 is At least three or more points on the outer periphery of the other surface side of the wafer are spaced apart from the first protrusion. , and The first susceptor is connected to the periphery the first susceptor has a disk-shaped first body portion, and the first protrusion stands upward from the first body portion; the second susceptor has a ring-shaped second body portion having an opening capable of accommodating the first body portion of the first susceptor, and the second protrusion protrudes from an edge of the opening of the second body portion toward a center thereof; the second susceptor has a third projection protruding downward from the second main body portion, The first projection is formed such that a distance between a lower end of the third projection and one surface of the second body portion is longer than a distance between an upper end of the first projection and the other surface of the first body portion. It is characterized by:

[0011] According to the susceptor of the present invention, the dividing portion between the first susceptor and the second susceptor is located outside the outer periphery of the wafer. Since there is no dividing portion below the wafer, the temperature distribution within the wafer can be made uniform.

[0013] In the susceptor of the present invention, the first projection may have a protruding height from one surface of the first main body portion that is greater than a thickness of a plate-shaped wafer hand that introduces the wafer into the susceptor.

[0016] In the susceptor of the present invention, the third protrusion of the second susceptor may have a protruding height from the other surface of the second main body portion that is greater than a thickness of a plate-shaped wafer hand that introduces the wafer into the susceptor.

[0017] In the susceptor of the present invention, a cover member may be placed on one surface of the second main body portion of the second susceptor.

[0018] In the susceptor of the present invention, the first projections and the second projections may be alternately arranged at intervals of 60° from each other in an annular region overlapping an outer circumferential edge portion of the other surface side of the wafer.

[0019] The outer peripheral edge of the wafer may be a ring-shaped region having a width of 10 mm or less from the edge to the center relative to the radius of the wafer.

[0020] The CVD apparatus of the present invention is characterized by comprising a film formation chamber having a susceptor as described above. Effect of the Invention

[0021] According to the present invention, it is possible to realize a susceptor capable of improving the in-plane uniformity of the wafer temperature, and a CVD apparatus including the susceptor. [Brief description of the drawings]

[0022] [Figure 1] 1 is a schematic diagram showing an example of a single-wafer processing type CVD apparatus provided with a susceptor according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a cross-sectional view showing an example of a process chamber (film forming furnace). [Diagram 3] 1 is a side cross-sectional view showing a susceptor according to an embodiment of the present invention. [Figure 4] 4 is an enlarged cross-sectional view of a main part of the susceptor shown in FIG. 3. [Diagram 5] FIG. 2 is a plan view of a susceptor according to an embodiment, as viewed from above. [Figure 6] 1A to 1C are cross-sectional views and perspective views showing step-by-step movements of a susceptor according to the present embodiment accompanying the movement of a wafer within a CVD apparatus. [Figure 7] 1A to 1C are cross-sectional views and perspective views showing step-by-step movements of a susceptor according to the present embodiment accompanying the movement of a wafer within a CVD apparatus. [Figure 8] 1A to 1C are cross-sectional views and perspective views showing step-by-step movements of a susceptor according to the present embodiment accompanying the movement of a wafer within a CVD apparatus. [Figure 9] 1A to 1C are cross-sectional views and perspective views showing step-by-step movements of a susceptor according to the present embodiment accompanying the movement of a wafer within a CVD apparatus. [Figure 10] 1A to 1C are cross-sectional views and perspective views showing step-by-step movements of a susceptor according to the present embodiment accompanying the movement of a wafer within a CVD apparatus. [Figure 11] 1A to 1C are cross-sectional views and perspective views showing step-by-step movements of a susceptor according to the present embodiment accompanying the movement of a wafer within a CVD apparatus. [Figure 12]1A to 1C are cross-sectional views and perspective views showing step-by-step movements of a susceptor according to the present embodiment accompanying the movement of a wafer within a CVD apparatus. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] The present embodiment will be described in detail below with reference to the drawings as appropriate. The drawings used in the following description may show characteristic parts in an enlarged scale for the sake of convenience in order to make the features of the present invention easier to understand, and the dimensional ratios of each component may differ from the actual ones. The materials, dimensions, etc. exemplified in the following description are merely examples, and the present invention is not limited thereto, and may be modified as appropriate within the scope of the effects of the present invention.

[0024] (CVD equipment) FIG. 1 is a schematic diagram showing an example of a single-wafer processing type CVD apparatus equipped with a susceptor according to one embodiment of the present invention. A chemical vapor deposition apparatus (CVD apparatus) 1 of this embodiment is an apparatus for growing a SiC single crystal epitaxial film on a wafer W by chemical vapor deposition. The CVD apparatus 1 according to this embodiment has a configuration in which a load lock chamber (loading / unloading chamber) 3 and a process chamber (film forming furnace) 5 are linearly connected via a transfer chamber 2.

[0025] Further, the transfer chamber 2, the load lock chamber 3, and the process chamber 5 are connected to a vacuum pump (not shown) for maintaining the internal spaces in a vacuum state.

[0026] The transfer chamber 2 has, for example, a rectangular shape in a plan view. A load lock chamber 3 is connected to one side of the transfer chamber 2 via a gate valve (not shown). A process chamber 5 is connected to the other side of the transfer chamber 2 via a gate valve (not shown).

[0027] A vacuum transfer robot 8 having a robot hand H is provided inside the transfer chamber 2, enabling the transfer and delivery of a wafer W and a susceptor, which will be described later, between the load lock chamber 3 and the process chamber 5.

[0028] The vacuum transfer robot 8 may be composed of, for example, a rotating shaft, an arm attached to the rotating shaft, a robot hand H attached to the tip of the arm, and a lifting mechanism for vertically moving the robot hand H. Note that multiple vacuum transfer robots 8 may be installed in the transfer chamber 2.

[0029] The load lock chamber 3 can switch the atmosphere of its internal space between an atmospheric pressure atmosphere and a vacuum atmosphere, and introduces and transfers the wafer W between the load lock chamber 3 and the outside in the atmospheric pressure atmosphere. Also, the wafer W is introduced and transferred by the robot hand H between the load lock chamber 3 and the transfer chamber 2 in the vacuum atmosphere.

[0030] A wafer W placed on a susceptor is introduced into a process chamber (film formation furnace) 5, and an epitaxial film is formed on one surface side of the wafer W. FIG. 2 is a cross-sectional view showing an example of a process chamber (film forming furnace). The process chamber (film formation furnace) 5 includes a susceptor 10 having a first susceptor 11 and a second susceptor 12, a furnace body 31 for growing a SiC single crystal epitaxial film on a wafer W placed on the first susceptor 11, a gas supply mechanism 32 for supplying a reactive gas into the inside of the furnace body 31, a lower heater 34 for heating the wafer W from below the susceptor 10, an upper heater 35 for heating the wafer W from above the susceptor 10, and a rotation mechanism 36 for rotating the wafer W.

[0031] Furthermore, the process chamber (film forming furnace) 5 of this embodiment has a gas exhaust part 37 that exhausts the reaction gas from the furnace body 31, and a gate valve G that serves as an opening for loading the wafer W into the furnace body 31.

[0032] In such a process chamber (film formation furnace) 5, the wafer W is heated by a lower heater 34 and an upper heater 35, and raw material gases such as silane as a silicon raw material, propane as a carbon raw material, hydrogen as a carrier gas, and nitrogen as a dopant are circulated from a gas supply mechanism 32. This allows a SiC single crystal epitaxial film to be grown on one side of the wafer W.

[0033] 1, in the CVD apparatus 1 of this embodiment, a wafer W is introduced from the outside, for example, a cassette (not shown) that accommodates a wafer W, into a transfer chamber 2 via a load lock chamber 3, and then placed on a first susceptor and introduced into a process chamber 5. Then, after a SiC single crystal epitaxial film is formed on one surface of the wafer W in the process chamber 5, the wafer W after the film formation moves in the opposite direction to the flow described above and is taken out of the CVD apparatus 1.

[0034] In this embodiment, the CVD apparatus 1 is shown as being configured with three chambers: the transfer chamber 2, the load lock chamber 3, and the process chamber 5. However, in addition to these, for example, it is also possible to provide the transfer chamber 2 with a mechanism for separating the wafer W from the susceptor 10, or to provide a chamber adjacent to the transfer chamber 2 for separating the wafer W from the susceptor 10.

[0035] (susceptor) Fig. 3 is a side cross-sectional view showing a susceptor according to one embodiment of the present invention, Fig. 4 is an enlarged cross-sectional view of a main part of the susceptor shown in Fig. 3, and Fig. 5 is a plan view of the susceptor according to one embodiment as viewed from above. The susceptor 10 is a wafer supporting member that holds a disk-shaped wafer W in the process chamber 5 (see FIG. 1) and moves the wafer W between the process chamber 5 and the transfer chamber 2. The susceptor 10 is made up of a first susceptor 11 and a second susceptor 12 arranged so as to surround the periphery of the first susceptor.

[0036] The first susceptor 11 includes a disk-shaped first main body portion 21 and a plurality of first protrusions 22 standing upward from the periphery of the first main body portion 21. The first protrusions 22 are formed, for example, in a cylindrical shape. The first protrusions 22 are formed at equal intervals along the periphery of the first main body portion 21, and in this embodiment, three first protrusions 22A, 22B, and 22C are formed at intervals of 120° from each other about the center. A distance is maintained between adjacent first protrusions 22 such that a robot hand H that moves a wafer W can be inserted and removed.

[0037] 4(a), each of the first projections 22 is formed at a position where its top portion contacts the outer circumferential edge portion We of the wafer W. The outer circumferential edge portion We of the wafer W may be, for example, a ring-shaped region that is outside a region Ws in which an integrated circuit pattern is formed after a SiC single crystal epitaxial film is formed, more specifically, a width of 10 mm, preferably 5 mm, and more preferably 3 mm or less from the periphery to the center relative to the radius of the wafer W.

[0038] The first protrusions 22 may be formed at four or more locations along the periphery of the first main body portion 21, so long as a gap is maintained between adjacent first protrusions 22 that allows the robot hand H to be inserted and removed. For example, the first protrusions 22 may be formed at four locations spaced at intervals of 90° from the center.

[0039] The first protrusion 22 is formed so that the protruding height from one surface 21a of the first main body portion 21 is greater than the thickness of the plate-shaped robot hand H. For example, when the thickness of the robot hand H is 2 to 3 mm, the height of the first protrusion 22 is formed to be 5 to 6 mm.

[0040] The first susceptor 11 may have a first main body 21 and a first protrusion 22 integrally formed therewith. The first susceptor 11 may be made of a material that can withstand high temperatures, such as graphite, SiC, Ta, Mo, or W, and may be made of a pure base material or a material coated with a carbide such as a SiC coat or a TaC coat.

[0041] The second susceptor 12 includes a second body portion 23, and a plurality of second projections 24 and a plurality of third projections 25 formed on the second body portion 23. The second body portion 23 is formed in a circular plate shape having an opening 23h capable of accommodating the first body portion 21. When the first susceptor 11 is inserted into the opening 23h of the second susceptor 12, the gap between the inner peripheral edge of the opening 23h and the peripheral edge of the first body portion 21 may be, for example, about 1 to 5 mm.

[0042] The second protrusions 24 are formed at three locations, namely, second protrusions 24A, 24B, and 24C, at equal intervals along the opening 23h of the second main body portion 23, and spaced apart from each other by 120° with respect to the center in this embodiment. The second protrusions 24A, 24B, and 24C are disposed at angles of 60° with respect to the first protrusions 22A, 22B, and 22C, respectively.

[0043] The third projections 25 are formed at equal intervals on the underside of the second main body portion 23, and in this embodiment, the three third projections 25A, 25B, and 25C are formed at the same positions as the second projections 24A, 24B, and 24C, spaced apart from each other by 120° with respect to the center. The third projections 25A, 25B, and 25C are disposed at angles of 60° from the first projections 22A, 22B, and 22C, respectively.

[0044] Each of the second projections 24 projects from an edge of the opening 23h of the second main body portion 23 toward the center. Each of the third projections 25 projects downward from the other surface 23b of the second main body portion 23. The first projections 22 and the third projections 25 are formed such that the distance L2 between the lower end of the third projection 25 and the one surface 23a of the second main body portion 23 shown in FIG. 4(b) is longer than the distance L1 between the upper end of the first projection 22 and the other surface 21b of the first main body portion 21 shown in FIG. 4(a) (L2>L1).

[0045] Each of the second protrusions 24 is formed, for example, in a cylindrical shape and contacts the outer circumferential edge portion We of the wafer W. The second protrusions 24 are formed at equal intervals along the edge portion of the opening 23h of the second main body portion 23, and in this embodiment, the second protrusions 24 are formed at three locations spaced at intervals of 120° from each other with respect to the center. The length of the second protrusions 24 is formed to be 5 to 6 mm toward the center of the opening 23h. Moreover, the highest portion of the second projection 24 is formed at the same position as one surface 23 a of the second main body portion 23 .

[0046] 4(b), each of the second projections 24 is formed at a position where its upper peripheral surface contacts the outer peripheral edge portion We of the wafer W. The outer peripheral edge portion We of the wafer W may be, for example, a ring-shaped region that is outside a region Ws in which a circuit pattern is formed after a SiC single crystal epitaxial film is formed, more specifically, a width of 10 mm, preferably 5 mm, and more preferably 3 mm or less from the periphery to the center relative to the radius of the wafer W.

[0047] Each third protrusion 25 is formed, for example, in a cylindrical shape and is formed at the same position as the second protrusion 24 formed on the second main body portion 23, at equal intervals along the edge of the opening 23h, and in this embodiment, in three locations spaced 120° apart from each other relative to the center.

[0048] The second protrusion 24 and the third protrusion 25 may be formed in four or more places along the edge of the opening 23h of the second main body portion 23. For example, the second protrusion 24 and the third protrusion 25 may be formed in four places spaced apart at 90° angles from the center.

[0049] Each of the third projections 25 is formed so that the protruding height from the other surface 23b of the second main body portion 23 is greater than the thickness of the plate-shaped robot hand H. For example, when the thickness of the robot hand H is 2 to 3 mm, the height of the third projections 25 is formed to be 5 to 6 mm.

[0050] The second susceptor 12 may have the second main body 23, the second projections 24, and the third projections 25 integrally formed therewith. The second susceptor 12 may be made of the same material as the first susceptor 11, that is, a solid base material that can withstand high temperatures, such as graphite, SiC, Ta, Mo, or W, or a material coated with a carbide such as SiC or TaC.

[0051] The first susceptor 11 and the second susceptor 12 constituting the susceptor 10 as described above are arranged at predetermined positions relative to each other along the circumferential direction. That is, the three first protrusions 22 formed on the first susceptor 11 and the three second protrusions 24 and the three third protrusions 25 formed on the second susceptor 12 are arranged at angles of 60° from each other with respect to the center.

[0052] In addition, when the first protrusions 22, the second protrusions 24, and the third protrusions 25 are formed in four locations each, the adjacent first protrusions 22, the second protrusions 24, and the third protrusions 25 may be formed at intervals of 45° relative to the center.

[0053] Moreover, it is preferable that a cover member 26 is further placed on one surface 23a of the second main body portion 23 constituting the second susceptor 12. Such a cover member 26 prevents an epitaxial film from being formed on one surface 23a of the second main body portion 23 during film formation in the process chamber 5. The cover member 26 is easily detachable from the second susceptor 12, and may be replaced with a new cover member 26 at any time after the epitaxial film is deposited.

[0054] The operation of the susceptor 10 of this embodiment configured as above and the process of forming a SiC single crystal epitaxial film using the CVD apparatus 1 will be described with reference to FIG. 1 and FIGS. 6 to 12 are cross-sectional views and perspective views showing step-by-step movements of the susceptor of this embodiment accompanying the movement of a wafer within a CVD apparatus. 6, the susceptor 10 is set in advance in the transfer chamber 2. In the transfer chamber 2, the other surface 21b side of the first main body portion 21 of the first susceptor 11 of the susceptor 10 is supported by a support pin 41.

[0055] The second susceptor 12 is held in a state in which the second projections 24 abut against the periphery of the one surface 21a side of the first main body portion 21 of the first susceptor 11 and the second susceptor 12 is engaged with the first susceptor 11. In this state, the first projections 22 of the first susceptor 11 protrude upward from the surface of the cover member 26 of the second susceptor 12.

[0056] In this state, a wafer W, which has been introduced from the outside via the load lock chamber 3 and supported by a robot hand H, is inserted into the transfer chamber 2, and the wafer W is supported directly above the first susceptor 11.

[0057] 7, the first susceptor 11 and the second susceptor 12 engaged with the periphery of the first susceptor 11 are raised by a push-up operation of the lift pins 42 of the transfer chamber 2. Then, the outer peripheral edge portion We of the wafer W comes into contact with the tops of the first protrusions 22 of the first susceptor 11. As a result, the wafer W is lifted up from the robot hand H, and the outer peripheral edge portion We is supported at three points by the three first protrusions 22A, 22B, 22C of the first susceptor 11. Thereafter, the robot hand H passes between the adjacent first projections 22 and exits to the outside of the susceptor 10.

[0058] Next, as shown in FIG. 8, the lift pins 42 (see FIG. 7) of the transfer chamber 2 are lowered, and the other surface 21b side of the first main body portion 21 of the first susceptor 11 that supported the wafer W is supported by the support pins 41 again.

[0059] 9, the robot hand H is introduced to the other surface 21b side of the first main body portion 21 of the first susceptor 11, passing between the adjacent third projections 25. Then, the robot hand H is raised, and with the wafer W supported by the three first projections 22A, 22B, 22C of the first susceptor 11, the robot hand H pulls out the susceptor 10 together with the wafer W from the transfer chamber 2, and moves the susceptor 10 supporting the wafer W to the process chamber 5.

[0060] As shown in FIG. 10, the susceptor 10 supporting the wafer W, which has been introduced into the process chamber 5, is guided above the stage 43 of the process chamber 5. 11, the first susceptor 11 is pushed upward from the other surface 21b side of the first main body portion 21 of the first susceptor 11 by the lift pins 44 of the process chamber 5, whereby the first susceptor 11 supporting the wafer W and the second susceptor 12 engaged with the periphery of the first susceptor 11 are raised. Then, the susceptor 10 is lifted up from the robot hand H. Thereafter, the robot hand H retreats to the outside of the process chamber 5.

[0061] 12, when the susceptor 10 is lowered to a position where the edge of the other surface 21b side of the first main body portion 21 of the first susceptor 11 abuts against the stage 43, the three third protrusions 25A, 25B, 25C (see also FIG. 5) of the second susceptor 12 abut against the upper surface of the stage 43. As a result, the second susceptor 12 moves upward with respect to the first susceptor 11. Then, the three second protrusions 24A, 24B, 24C (see also FIG. 5) are positioned above the first protrusions 22, and the outer circumferential edge portion We (see FIG. 4(b)) of the wafer W is supported at three points by the three second protrusions 24A, 24B, 24C of the second susceptor 12.

[0062] In this manner, in the process chamber 5, with the wafer W supported by the three second protrusions 24A, 24B, 24C (see also FIG. 5) of the second susceptor 12, a SiC single crystal epitaxial film is formed on one surface side of the wafer W.

[0063] The characteristics of the epitaxial film reflect the temperature distribution resulting from the susceptor shape. To achieve uniform characteristics in the circumferential direction, it is desirable for the shape of the susceptor to be symmetrical in the circumferential direction. With uniform characteristics in the circumferential direction, the characteristic inspection can be performed by inspecting one row in the diameter direction to obtain representative inspection values, which is effective in increasing the throughput of characteristic inspections.

[0064] In this embodiment as well, when a SiC single crystal epitaxial film is formed on one side of the wafer W in the process chamber 5, the characteristics of the epitaxial film reflect the temperature distribution resulting from the susceptor shape. In the susceptor 10 of this embodiment, the dividing portion between the first susceptor 11 and the second susceptor 12 is located outside the outer periphery We of the wafer W.

[0065] Therefore, there are no seams or protrusions on the first main body portion 21 of the first susceptor 11 disposed opposite the other surface W2 of the wafer W. This makes it possible to improve the in-plane uniformity of the wafer temperature.

[0066] Further, the second protrusions 24 formed on the second susceptor 12 are formed at positions where the highest parts are lower than the surface of the cover member 26 (see FIG. 4(b)). Furthermore, since a gap is formed between the first susceptor 11 and the second susceptor 12 outside the outer peripheral edge portion We of the wafer W, it is possible to prevent the wafer from floating up due to gas accumulation during epitaxial growth without forming a notch or the like in the first body portion 21 of the first susceptor 11.

[0067] After the SiC single crystal epitaxial film is formed on one side of the wafer W, the movement of the susceptor 10 described above is reversed, and the wafer W after film formation is stored in an external device, such as a cassette (not shown), via the load lock chamber 3.

[0068] Although the embodiments of the present invention have been described above, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope of the invention and its equivalents described in the claims, as well as in the scope and spirit of the invention. [Explanation of symbols]

[0069] 1...CVD equipment 2. Transfer chamber 3...Load lock chamber (load / unload chamber) 5...Process chamber (film deposition furnace) 10…Susceptor 11...First susceptor 12...Second susceptor 21...First main body part 22,22A,22B,22C…1st protrusion 23...Second body part 24,24A,24B,24C…2nd protrusion 25,25A,25B,25C…3rd protrusion H...Robot hand W…wafer

Claims

1. A susceptor for holding a disk-shaped wafer in a CVD apparatus for forming a film on one side of the wafer by chemical vapor deposition, comprising: The susceptor includes a first susceptor and a second susceptor disposed so as to surround the first susceptor, a first protrusion is formed on the first susceptor, and a top of the first protrusion is capable of contacting at least three or more points of an outer circumferential edge portion of the other surface side of the wafer; a second protrusion is formed on the second susceptor, and a peripheral surface of the second protrusion 24 is capable of contacting at least three or more points of the outer peripheral edge portion of the other surface side of the wafer that are spaced apart from the first protrusion, and the peripheral edge of the first susceptor; the first susceptor has a disk-shaped first main body portion, and the first protrusion is provided upright upward from the first main body portion, the second susceptor has a second body portion having a circular plate shape and an opening capable of accommodating the first body portion of the first susceptor, and the second protrusion protrudes from an edge portion of the opening of the second body portion toward a center portion thereof, the second susceptor has a third projection protruding downward from the second main body portion, A susceptor characterized in that the first protrusion is formed so that the distance between the lower end of the third protrusion and one surface of the second main body portion is longer than the distance between the upper end of the first protrusion and the other surface of the first main body portion.

2. 2 . The susceptor according to claim 1 , wherein the first projection has a protruding height from one surface of the first body portion that is greater than a thickness of a plate-shaped wafer hand that introduces the wafer into the susceptor.

3. A susceptor as described in claim 1 or 2, characterized in that the third protrusion of the second susceptor has a protruding height from the other surface of the second main body portion that is greater than the thickness of a plate-shaped wafer hand that introduces the wafer into the susceptor.

4. 3. The susceptor according to claim 1, wherein a cover member is placed on one surface of the second body portion of the second susceptor.

5. 3. The susceptor according to claim 1, wherein the first protrusions and the second protrusions are alternately arranged at intervals of 60° from each other in a circular region overlapping the outer peripheral edge portion of the other surface side of the wafer.

6. 3. The susceptor according to claim 1, wherein the outer peripheral portion of the wafer is a ring-shaped region having a width of 10 mm or less from the peripheral portion to the center of the wafer relative to a radius of the wafer.

7. A CVD apparatus comprising a film-forming chamber having the susceptor according to any one of claims 1 to 6.

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