JP7619019B2 - Susceptor, CVD equipment - Google Patents

Description

The present invention relates to a susceptor that supports a wafer and a CVD apparatus.

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

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 or other methods, and the SiC epitaxial film is formed using a chemical vapor deposition (CVD) device.

One example of such a CVD device is one that has a susceptor that rotates around a rotation axis. By rotating the wafer placed on the susceptor, the gas supply state in the in-plane direction can be made 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 backside, and reactive gas is supplied from above to the wafer surface to form a film.

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, and an outer susceptor that has an opening in the center and can accommodate the inner susceptor in the opening.

JP 2009-70915 A

In order to deposit a smooth film of uniform thickness using a film deposition system (CVD system), it is important to keep the temperature uniform across one surface of the wafer (growth surface) during film deposition. If the temperature across the wafer is not uniform, there is a concern that the thickness of the film formed and the distribution of the doping concentration will be non-uniform, that stress will be placed on the wafer, causing it to warp more, or that stress will be placed on the wafer, resulting in the generation of new crystal defects such as dislocations.

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.

The present invention was made in consideration of these circumstances, and aims to realize a susceptor that can make the temperature of the wafer uniform across its surface, and a CVD apparatus equipped with the susceptor.

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 is composed of a first susceptor and a second susceptor arranged so as to surround the periphery of 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 the outer peripheral edge portion on the other side of the wafer, a second protrusion is formed on the second susceptor, and a peripheral surface of the second protrusion 24 is 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 outer peripheral edge of the first susceptor , the first susceptor has a disk-shaped first main body portion, and the first protrusion stands upward from the first main body portion, the second susceptor has a circular plate-shaped second main body portion having an opening capable of accommodating the first main body portion of the first susceptor, and the second protrusion protrudes from the edge of the opening of the second main body portion toward the center,
the second susceptor has a third projection protruding downward from the second main body portion,
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 .

With 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, it is possible to achieve a uniform temperature distribution within the wafer surface.

In addition, in the susceptor of the present invention, the height of the first protrusion protruding from one surface of the first body portion may be greater than the thickness of a plate-shaped wafer hand that introduces the wafer into the susceptor.

In addition, 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 the thickness of a plate-shaped wafer hand that introduces the wafer into the susceptor.

In addition, in the susceptor of the present invention, a cover member may be placed on one surface of the second body portion of the second susceptor.

In addition, in the susceptor of the present invention, the first protrusions and the second protrusions may be arranged alternately at intervals of 60° from each other in an annular region that overlaps with the outer peripheral edge portion of the other side of the wafer.

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

The CVD apparatus of the present invention is characterized by being equipped with a deposition chamber having a susceptor as described in each of the above paragraphs.

The present invention makes it possible to realize a susceptor capable of improving the uniformity of the wafer temperature across its surface, and a CVD apparatus equipped with the susceptor.

1 is a schematic diagram showing an example of a single-wafer processing type CVD apparatus equipped with a susceptor according to an embodiment of the present invention. FIG. 2 is a cross-sectional view showing an example of a process chamber (film forming furnace). 1 is a side cross-sectional view showing a susceptor according to an embodiment of the present invention. FIG. 4 is an enlarged cross-sectional view of a main portion of the susceptor shown in FIG. 3 . FIG. 2 is a top plan view of a susceptor according to an embodiment; 1A to 1C are cross-sectional views and perspective views showing step-by-step movements of a susceptor according to an embodiment of the present invention as a wafer moves within a CVD apparatus. 1A to 1C are cross-sectional views and perspective views showing step-by-step movements of a susceptor according to an embodiment of the present invention as a wafer moves within a CVD apparatus. 1A to 1C are cross-sectional views and perspective views showing step-by-step movements of a susceptor according to an embodiment of the present invention as a wafer moves within a CVD apparatus. 1A to 1C are cross-sectional views and perspective views showing step-by-step movements of a susceptor according to an embodiment of the present invention as a wafer moves within a CVD apparatus. 1A to 1C are cross-sectional views and perspective views showing step-by-step movements of a susceptor according to an embodiment of the present invention as a wafer moves within a CVD apparatus. 1A to 1C are cross-sectional views and perspective views showing step-by-step movements of a susceptor according to an embodiment of the present invention as a wafer moves within a CVD apparatus. 1A to 1C are cross-sectional views and perspective views showing step-by-step movements of a susceptor according to an embodiment of the present invention as a wafer moves within a CVD apparatus.

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 enlarged characteristic parts 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 to them, and can be modified as appropriate within the scope of its effects.

(CVD Apparatus)
FIG. 1 is a schematic diagram showing an example of a single-wafer processing type CVD apparatus equipped with a susceptor according to an 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 connected in a straight line via a transfer chamber 2 .

In addition, a vacuum pump (not shown) is connected to the transfer chamber 2, the load lock chamber 3, and the process chamber 5 to maintain the internal space in a vacuum state.

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).

Inside the transfer chamber 2, a vacuum transfer robot 8 having a robot hand H is provided, enabling the transfer and delivery of wafers W and susceptors (described later) between the load lock chamber 3 and the process chamber 5.

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 moving the robot hand H in the vertical direction. Note that multiple vacuum transfer robots 8 can be installed in the transfer chamber 2.

The atmosphere of the internal space of the load lock chamber 3 can be switched between atmospheric pressure and vacuum, and the wafer W is introduced and removed from the outside in an atmospheric pressure atmosphere. The wafer W is also introduced and removed from the transfer chamber 2 by the robot hand H in a vacuum atmosphere.

A wafer W placed on a susceptor is introduced into a process chamber (film-forming furnace) 5, and an epitaxial film is formed on one surface 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.

Furthermore, the process chamber (film forming furnace) 5 of this embodiment has a gas exhaust section 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.

In such a process chamber (film-forming furnace) 5, the wafer W is heated by a lower heater 34 and an upper heater 35, and raw material gases such as silane, which is a silicon raw material, propane, which is a carbon raw material, hydrogen, which is a carrier gas, and nitrogen, which is 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.

As shown in FIG. 1, in the CVD apparatus 1 of this embodiment, a wafer W is introduced from the outside, for example, a cassette (not shown) that contains 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 side of the wafer W in the process chamber 5, the wafer W after film formation moves in the opposite direction to the flow described above and is taken out of the CVD apparatus 1.

In this embodiment, the CVD apparatus 1 is configured with three chambers: the transfer chamber 2, the load lock chamber 3, and the process chamber 5. However, in addition to this, 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.

(Susceptor)
Fig. 3 is a side cross-sectional view showing a susceptor according to an 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 the 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.

The first susceptor 11 comprises a disk-shaped first main body portion 21 and a number 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 so that a robot hand H that moves the wafer W can be inserted and removed.

As shown in FIG. 4(a), each of the first protrusions 22 is formed at a position where its top contacts the outer peripheral portion We of the wafer W. The outer peripheral portion We of the wafer W may be, for example, a ring-shaped region that is outside the region Ws where an integrated circuit pattern is formed after the 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.

The first protrusions 22 may be formed in four or more locations along the periphery of the first main body portion 21, as 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 in four locations spaced at 90° intervals from the center.

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.

The first susceptor 11 may be made of a first main body 21 and a first protrusion 22 that are integrally formed. The first susceptor 11 may be made of 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.

The second susceptor 12 comprises a second body portion 23, and a plurality of second protrusions 24 and a plurality of third protrusions 25 formed on the second body portion 23. The second body portion 23 is formed in the shape of an annular plate 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.

The second protrusions 24 are formed at equal intervals along the opening 23h of the second main body portion 23. In this embodiment, three second protrusions 24A, 24B, and 24C are formed at intervals of 120° from each other relative to the center. The second protrusions 24A, 24B, and 24C are disposed at angles of 60° from the first protrusions 22A, 22B, and 22C, respectively.

The third protrusions 25 are formed at equal intervals on the underside of the second main body portion 23. In this embodiment, the third protrusions 25A, 25B, and 25C are formed at the same positions as the second protrusions 24A, 24B, and 24C, spaced apart from each other at 120° from the center. The third protrusions 25A, 25B, and 25C are arranged at angles of 60° from the first protrusions 22A, 22B, and 22C, respectively.

Each of the second protrusions 24 protrudes from the edge of the opening 23h of the second main body portion 23 toward the center. Also, each of the third protrusions 25 protrudes downward from the other surface 23b of the second main body portion 23. The first protrusions 22 and the third protrusions 25 are formed so that the distance L2 between the lower end of the third protrusion 25 shown in FIG. 4(b) and one surface 23a of the second main body portion 23 is longer than the distance L1 between the upper end of the first protrusion 22 shown in FIG. 4(a) and the other surface 21b of the first main body portion 21 (L2>L1).

Each of the second protrusions 24 is formed, for example, in a cylindrical shape and contacts the outer peripheral 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 the center. The length of the second protrusions 24 is formed to be 5 to 6 mm toward the center of the opening 23h.
The highest portion of the second projection 24 is formed at the same position as the first surface 23 a of the second main body portion 23 .

As shown in FIG. 4(b), each of the second protrusions 24 is formed at a position where the upper part of its 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 the region Ws where the circuit pattern is formed after the 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.

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

The second protrusion 24 and the third protrusion 25 may be formed in four or more locations 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 locations spaced at 90° intervals from the center.

Each third protrusion 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 protrusion 25 is formed to be 5 to 6 mm.

The second susceptor 12 may be made of the second body 23, the second protrusion 24, and the third protrusion 25, which are integrally formed. The second susceptor 12 may be made of the same material as the first susceptor 11, i.e., 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.

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 relative to the center.

When the first protrusions 22, the second protrusions 24, and the third protrusions 25 are formed in four locations each, the first protrusions 22, the second protrusions 24, and the third protrusions 25 that are adjacent to each other may be formed at intervals of 45° from the center.

It is also preferable that a cover member 26 is 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 can be easily attached and detached from the second susceptor 12, and can be replaced with a new cover member 26 at any time after the epitaxial film is deposited.

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.
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 the wafer within the 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 the support pins 41.

The second susceptor 12 is held in a state in which the second protrusion 24 abuts against the periphery of one surface 21a of the first 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 protrusion 22 of the first susceptor 11 protrudes upward from the surface of the cover member 26 of the second susceptor 12.

In this state, a wafer W, which has been introduced from the outside via the load lock chamber 3 and is 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.

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 periphery 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 periphery 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 .

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 of the first body portion 21 of the first susceptor 11 supporting the wafer W is supported again by the support pins 41.

Next, as shown in FIG. 9, the robot hand H is introduced to the other surface 21b of the first body portion 21 of the first susceptor 11, passing between the adjacent third protrusions 25. Then, the robot hand H is raised, and with the wafer W supported by the three first protrusions 22A, 22B, 22C of the first susceptor 11, the robot hand H pulls out the susceptor 10 from the transfer chamber 2, and moves the susceptor 10 supporting the wafer W to the process chamber 5.

As shown in FIG. 10, the susceptor 10 supporting the wafer W, which has been introduced into the process chamber 5 , is guided to 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.

Next, as shown in FIG. 12, when the susceptor 10 is lowered to a position where the edge of the other surface 21b of the first 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. This causes the second susceptor 12 to move upward relative 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 peripheral 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.

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

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.

In this embodiment, 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 this embodiment, the susceptor 10 has a division portion between the first susceptor 11 and the second susceptor 12 located outside the outer peripheral edge portion We of the wafer W.

Therefore, the first body portion 21 of the first susceptor 11, which is arranged opposite the other surface W2 of the wafer W, does not have any seams or protrusions. This makes it possible to improve the in-plane uniformity of the wafer temperature.

The second protrusions 24 formed on the second susceptor 12 are formed at a position where the highest part is lower than the surface of the cover member 26 (see FIG. 4(b)). 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, so that the wafer can be prevented 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.

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.

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 gist of the invention. These embodiments and their modifications are within the scope of the invention and its equivalents as set forth in the claims, as well as the scope and gist of the invention.

1... CVD device 2... Transfer chamber 3... Load lock chamber (load-in/load-out chamber)
5...Process chamber (film forming furnace)
REFERENCE SIGNS LIST 10 susceptor 11 first susceptor 12 second susceptor 21 first main body portion 22, 22A, 22B, 22C first projection 23 second main body portion 24, 24A, 24B, 24C second projection 25, 25A, 25B, 25C third projection H robot hand W wafer

Claims (7)

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 . 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. The susceptor according to claim 1 or 2, characterized in that the protruding height of the third protrusion of the second susceptor from the other surface of the second body is greater than the thickness of a plate-shaped wafer hand that introduces the wafer into the susceptor. 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. The susceptor according to claim 1 or 2, characterized in that the first protrusions and the second protrusions are alternately arranged at intervals of 60° from each other in an annular region that overlaps the outer peripheral edge of the other side of the wafer. The susceptor according to claim 1 or 2, characterized in that the outer peripheral edge of the wafer is 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. A CVD apparatus comprising a deposition chamber having a susceptor according to any one of claims 1 to 6.

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