JP2022083011A - Susceptor and cvd equipment - Google Patents

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

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

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

The SiC epitaxial wafer is manufactured by growing a SiC epitaxial film, which is an active region of a SiC semiconductor device, on a SiC substrate (SiC wafer). The SiC wafer is obtained by processing from a bulk single crystal of SiC produced by a sublimation method or the like, and the SiC epitaxial film is formed by a chemical vapor deposition (CVD) device.

As an example of such a CVD device, there is a device having a susceptor that rotates about a rotation axis. By rotating the wafer placed on the susceptor, the gas supply state in the in-plane direction can be made uniform, and a uniform epitaxial film can be grown on the SiC substrate. The wafer is transported inside the CVD apparatus and placed on the susceptor using a manual or automatic transfer mechanism. The susceptor on which the wafer is placed is heated from the back surface, and the reaction gas is supplied to the wafer surface from above to form a film.

As the susceptor, a susceptor having a separated structure of an inner susceptor and an outer susceptor is known (see, for example, Patent Document 1). The susceptor shown in Patent Document 1 has an inner susceptor which is smaller than the diameter of the wafer and has a convex portion for mounting the wafer on the surface, and an opening in the center, and the inner susceptor can be accommodated in the opening. It consists of an outer susceptor.

Japanese Unexamined Patent Publication No. 2009-70915

In order to form a smooth film with a uniform thickness using a film forming device (CVD device), it is important to make the temperature of one surface (growth surface) of the wafer uniform during film formation. be. If the in-plane temperature of the wafer is non-uniform, the thickness of the formed film and the distribution of the doping concentration become non-uniform, the wafer is stressed and warped, and the wafer is stressed and dislocations occur. There is a concern that new crystal defects will occur.

However, in the case of a susceptor as shown in Patent Document 1, the inner susceptor and the outer susceptor tend to have different temperatures, and as a result, the in-plane temperature of the wafer tends to be non-uniform. There are problems that this temperature non-uniformity leads to non-uniformity in the in-plane distribution of film thickness / doping concentration, deterioration of wafer warpage, and increase of crystal defects.

The present invention has been made in consideration of such circumstances, and an object of the present invention is to realize a susceptor capable of making the temperature of a wafer uniform in the plane, and a CVD apparatus provided 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 that holds a wafer in a CVD device that forms a film on one side of a disk-shaped wafer by chemical vapor deposition, and the susceptor is a first susceptor and the first susceptor. It consists of a second susceptor arranged so as to surround the periphery of one susceptor, and the first susceptor is formed with a first protrusion that is in contact with at least three or more of the outer peripheral edges on the other surface side of the wafer. The second susceptor is in contact with the second susceptor at at least three places on the other side of the wafer, which are spaced apart from the first protrusion, and is in contact with the peripheral edge of the first susceptor. It is characterized in that protrusions are formed.

According to the susceptor of the present invention, the divided portion between the first susceptor and the second susceptor is outside the outer peripheral edge portion of the wafer. Since there is no divided portion below the wafer, it is possible to make the in-plane temperature distribution of the wafer uniform.

Further, in the susceptor of the present invention, even if the first susceptor has a disk-shaped first main body portion and the first protrusion is erected upward from the peripheral edge of the first main body portion. good.

Further, in the susceptor of the present invention, the protrusion height of the first protrusion from one surface of the first main body portion may be larger than the thickness of the plate-shaped wafer hand that introduces the wafer into the susceptor.

Further, in the susceptor of the present invention, the second susceptor has a ring 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 has a second main body portion. It may be projected from the edge portion of the opening of the second main body portion toward the central portion.

Further, in the susceptor of the present invention, the second susceptor may have a third protrusion protruding downward from the second main body portion.

Further, in the susceptor of the present invention, the protrusion height of the third projection of the second susceptor from the other surface of the second main body is larger than the thickness of the plate-shaped wafer hand that introduces the wafer into the susceptor. May also be large.

Further, 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.

Further, in the susceptor of the present invention, the first protrusion and the second protrusion are alternately arranged at intervals of 60 ° from each other in the annular region overlapping the outer peripheral edge portion on the other surface side of the wafer. May be good.

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

The CVD apparatus of the present invention is characterized by comprising a film forming chamber having the susceptor described in each of the above items.

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.

It is a schematic block diagram which shows an example of the single-wafer processing type CVD apparatus provided with the susceptor which concerns on one Embodiment of this invention. FIG. 2 is a cross-sectional view showing an example of a process chamber (film forming furnace). It is a side sectional view which shows the susceptor of one Embodiment of this invention. FIG. 3 is an enlarged cross-sectional view of a main part of the susceptor shown in FIG. It is a top view of the susceptor of one embodiment in a state of looking down. It is sectional drawing and the perspective view which showed the movement of the susceptor of this embodiment stepwise with the movement of a wafer in a CVD apparatus. It is sectional drawing and the perspective view which showed the movement of the susceptor of this embodiment stepwise with the movement of a wafer in a CVD apparatus. It is sectional drawing and the perspective view which showed the movement of the susceptor of this embodiment stepwise with the movement of a wafer in a CVD apparatus. It is sectional drawing and the perspective view which showed the movement of the susceptor of this embodiment stepwise with the movement of a wafer in a CVD apparatus. It is sectional drawing and the perspective view which showed the movement of the susceptor of this embodiment stepwise with the movement of a wafer in a CVD apparatus. It is sectional drawing and the perspective view which showed the movement of the susceptor of this embodiment stepwise with the movement of a wafer in a CVD apparatus. It is sectional drawing and the perspective view which showed the movement of the susceptor of this embodiment stepwise with the movement of a wafer in a CVD apparatus.

Hereinafter, the present embodiment will be described in detail with reference to the drawings as appropriate. The drawings used in the following description may be enlarged for convenience in order to make the features of the present invention easy to understand, and the dimensional ratios of each component may differ from the actual ones. be. The materials, dimensions, and the like exemplified in the following description are examples, and the present invention is not limited thereto, and can be appropriately modified and carried out within the range in which the effect is exhibited.

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

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

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). Further, a process chamber 5 is connected to the other side of the transfer chamber 2 via a gate valve (not shown).

A vacuum transfer robot 8 having a robot hand H is provided inside the transfer chamber 2, and the wafer W and the susceptor described later can be transferred and transferred between the load lock chamber 3 and the process chamber 5. Has been done.

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 an elevating mechanism for moving the robot hand H in the vertical direction. Just do it. A plurality of vacuum transfer robots 8 can be installed in the transfer chamber 2.

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

In the process chamber (deposition furnace) 5, the wafer W placed on the susceptor is introduced, 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 (deposition furnace).
The process chamber (deposition furnace) 5 includes a susceptor 10 having a first susceptor 11 and a second susceptor 12, and 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 that supplies a reaction gas to the inside of the furnace body 31, a lower heater 34 that heats the wafer W from the lower part of the susceptor 10, an upper heater 35 that heats the wafer W from above the susceptor 10, and a wafer W. A rotation mechanism 36 for rotating the wafer is provided.

Further, the process chamber (deposition furnace) 5 of the present embodiment has a gas discharge unit 37 for discharging the reaction gas from the furnace body 31 and a gate valve G serving as an opening for carrying the wafer W into the furnace body 31. And have.

In such a process chamber (deposition furnace) 5, the wafer W is heated by the lower heater 34 and the upper heater 35, and from the gas supply mechanism 32, silane as a silicon raw material, propane as a carbon raw material, and hydrogen as a carrier gas are used. , Raw material gas such as nitrogen which is a dopant is circulated. This makes it possible to grow a SiC single crystal epitaxial film on one side of the wafer W.

As shown in FIG. 1, in the CVD apparatus 1 of the present embodiment, the wafer W introduced into the transfer chamber 2 from the outside, for example, from a cassette (not shown) accommodating the wafer W via the load lock chamber 3, is first. After being placed on the susceptor, it is introduced into the process chamber 5. Then, after the SiC single crystal epitaxial film is formed on one surface side of the wafer W in the process chamber 5, the formed wafer W moves in the direction opposite to the above-mentioned flow and is taken out to the outside of the CVD apparatus 1. ..

In the present embodiment, the CVD device 1 is configured to include three chambers, a transfer chamber 2, a load lock chamber 3, and a process chamber 5. In addition to this, for example, a wafer W is added to the transfer chamber 2. A mechanism for separating the wafer W and the susceptor 10 may be provided, or a chamber for separating the wafer W and the susceptor 10 may be provided adjacent to the transfer chamber 2.

(Suceptor)
FIG. 3 is a side sectional view showing a susceptor according to an embodiment of the present invention. Further, FIG. 4 is an enlarged cross-sectional view of a main part of the susceptor shown in FIG. Further, FIG. 5 is a plan view of the susceptor of one embodiment looking down from above.
The susceptor 10 is a wafer support member that holds the disc-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 includes a first susceptor 11 and a second susceptor 12 arranged so as to surround the circumference of the first susceptor.

The first susceptor 11 includes a disk-shaped first main body portion 21 and a plurality of first protrusions 22 erected upward from the peripheral edge of the first main body portion 21. The first protrusion 22 is formed, for example, in a cylindrical shape. The first protrusions 22 are formed at equal intervals along the peripheral edge of the first main body portion 21, and in the present embodiment, three first protrusions 22A, 22B, 22C are formed at intervals of 120 ° with respect to the center. Has been done. Between the first protrusions 22 adjacent to each other, a distance is maintained so that the robot hand H for moving the wafer W can be inserted and removed.

As shown in FIG. 4A, each first projection 22 is formed at a position at the top thereof in contact with the outer peripheral edge portion We of the wafer W. The outer peripheral edge portion We of the wafer W is, for example, outside the region Ws forming the integrated circuit pattern after the SiC single crystal epitaxial film is formed, and more specifically, from the peripheral edge to the center with respect to the radius of the wafer W. It may be a ring-shaped region having a width of 10 mm, preferably 5 mm, and more preferably 3 mm or less toward the surface.

It should be noted that the first protrusions 22 are formed at four or more locations along the peripheral edge of the first main body portion 21 as long as the distance between the first protrusions 22 adjacent to each other so that the robot hand H can be inserted and removed is maintained. May be. For example, the first protrusions 22 can be formed at four locations with an interval of 90 ° from the center.

The first protrusion 22 is formed so that the height of protrusion from one surface 21a of the first main body 21 is larger 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.

In the first susceptor 11, the first main body portion 21 and the first protrusion 22 may be integrally formed. As the constituent material of the first susceptor 11, a solid base material that can withstand high temperatures such as graphite, SiC, Ta, Mo, and W, or a material coated with a carbide such as a SiC coat or a TaC coat can be used. ..

The second susceptor 12 includes a second main body portion 23, a plurality of second protrusions 24 formed on the second main body portion 23, and a plurality of third protrusions 25. The second main body portion 23 is formed in the shape of an annulus plate having an opening 23h capable of accommodating the first main 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 main body 21 may be, for example, about 1 to 5 mm. ..

The second protrusions 24 have three second protrusions 24A, 24B, and 24C at equal intervals along the opening 23h of the second main body 23, and at intervals of 120 ° with respect to the center in the present embodiment. It is formed. The second protrusions 24A, 24B, and 24C are arranged at an angle of 60 ° with respect to the first protrusions 22A, 22B, and 22C, respectively.

The third protrusions 25 are equally spaced on the lower surface of the second main body 23, and in the present embodiment, are spaced 120 ° from each other with respect to the center, and are provided at three positions at the same positions as the second protrusions 24A, 24B, and 24C. Third protrusions 25A, 25B, 25C are formed. The third protrusions 25A, 25B, and 25C are arranged at an angle of 60 ° with respect to the first protrusions 22A, 22B, and 22C, respectively.

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

Each second protrusion 24 is formed in a cylindrical shape, for example, and is in contact with the outer peripheral edge portion We of the wafer W. The second protrusions 24 are formed at three positions at equal intervals along the edge of the opening 23h of the second main body portion 23, and at intervals of 120 ° with respect to the center in the present embodiment. The length of the second protrusion 24 is 5 to 6 mm toward the center of the opening 23h.
Further, the highest portion of the second protrusion 24 is formed at the same position as the one surface 23a of the second main body portion 23.

As shown in FIG. 4B, each of the second protrusions 24 is formed at a position in contact with the outer peripheral edge portion We of the wafer W at the upper portion of the peripheral surface thereof. The outer peripheral edge portion We of the wafer W is, for example, outside the region Ws on which the circuit pattern is formed after the SiC single crystal epitaxial film is formed, and more specifically, from the peripheral edge to the center with respect to the radius of the wafer W. It may be a ring-shaped region having a width of 10 mm, preferably 5 mm, and more preferably 3 mm or less.

Each of the third protrusions 25 is formed in a cylindrical shape, for example, 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 the present embodiment, each other. It is formed in three places with an interval of 120 ° from the center.

The second protrusion 24 and the third protrusion 25 may be formed at 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 can be formed at four locations with an interval of 90 ° from the center.

Each third protrusion 25 is formed so that the height of protrusion from the other surface 23b of the second main body 23 is larger 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 formed by integrally forming the second main body portion 23, the second protrusion 24, and the third protrusion 25. As the constituent material of the second susceptor 12, the same material as the first susceptor 11, that is, a solid base material capable of withstanding high temperatures such as graphite, SiC, Ta, Mo, W, etc., or a SiC coat, a TaC coat, or the like is used. A material coated with carbide can be used.

The first susceptor 11 and the second susceptor 12 constituting the susceptor 10 as described above are arranged at predetermined positions with 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 third protrusions 25 formed on the second susceptor 12 are 60 ° each with respect to the center. It is placed at an angle of.

When the first protrusion 22 and the second protrusion 24 and the third protrusion 25 are formed at four locations, the first protrusion 22, the second protrusion 24, and the third protrusion 25, which are adjacent to each other, are centered. It may be formed at an interval of 45 ° with respect to the above.

Further, it is preferable that the cover member 26 is further mounted 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 23 at the time of film formation in the process chamber 5. The cover member 26 can be easily attached to and detached from the second susceptor 12, and may be replaced with a new cover member 26 at an arbitrary timing after the epitaxial film is deposited.

The operation of the susceptor 10 of the present embodiment having the above configuration will be described with reference to FIGS. 1 and 6 to 12 regarding the step of forming the SiC single crystal epitaxial film by the CVD apparatus 1.
6 to 12 are cross-sectional views and perspective views showing the movement of the susceptor of the present embodiment stepwise with the movement of the wafer in the CVD apparatus.
First, as shown in FIG. 6, the susceptor 10 is set in the transfer chamber 2 in advance. In the transfer chamber 2, the susceptor 10 is supported by the support pin 41 on the other surface 21b side of the first main body portion 21 of the first susceptor 11.

Then, the second susceptor 12 is held in a state where the second protrusion 24 abuts on the peripheral edge of the first main body 21 of the first susceptor 11 on the one side 21a side, and the second susceptor 12 is engaged with the first susceptor 11. To. 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.

Then, in this state, the wafer W introduced from the outside via the load lock chamber 3 and supported by the robot hand H is inserted into the transfer chamber 2, and the wafer W is directly above the first susceptor 11. Be supported.

Next, as shown in FIG. 7, the push-up operation by the lift pin 42 of the transfer chamber 2 raises the first susceptor 11 and the second susceptor 12 engaged with the peripheral edge of the first susceptor 11. Then, the outer peripheral edge portion We of the wafer W abuts on the top of the first projection 22 of the first susceptor 11. As a result, the wafer W is lifted from the robot hand H, and the outer peripheral edge portion We is supported at three points by the three first projections 22A, 22B, and 22C of the first susceptor 11.
After that, the robot hand H exits to the outside of the susceptor 10 through the space between the first protrusions 22 adjacent to each other.

Next, as shown in FIG. 8, the lift pin 42 (see FIG. 7) of the transfer chamber 2 is lowered, and the other surface 21b side of the first main body 21 of the first susceptor 11 supporting the wafer W is on the support pin 41. It will be supported again.

Next, as shown in FIG. 9, the robot hand H is introduced on the other surface 21b side of the first main body portion 21 of the first susceptor 11 through the space between the third projections 25 adjacent to each other. Then, the robot hand H is raised, and the wafer W is pulled out from the transfer chamber 2 by the robot hand H together with the susceptor 10 in a state of being supported by the three first projections 22A, 22B, 22C of the first susceptor 11, and the process chamber. The susceptor 10 supporting the wafer W is moved to 5.

As shown in FIG. 10, the susceptor 10 supporting the wafer W introduced into the process chamber 5 is guided above the stage 43 of the process chamber 5.
Then, as shown in FIG. 11, the wafer W is supported by pushing the first susceptor 11 upward by the lift pin 44 of the process chamber 5 from the other surface 21b side of the first main body 21 of the first susceptor 11. The first susceptor 11 and the second susceptor 12 engaged with the peripheral edge of the first susceptor 11 rise. Then, the susceptor 10 floats from the robot hand H. After this, the robot hand H exits 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 portion on the other surface 21b side of the first main body portion 21 of the first susceptor 11 abuts on the stage 43, the three susceptors 12 are three. The third protrusions 25A, 25B, 25C (see also FIG. 5) abut on 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 located above the first protrusion 22, and the wafer W has the three second protrusions 24A, 24B of the second susceptor 12. , 24C supports the outer peripheral edge We (see FIG. 4B) at three points.

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

The properties of the epitaxial film reflect the temperature distribution derived from the susceptor shape. In order to realize uniform characteristics in the circumferential direction, it is desirable that the shape of the susceptor is symmetrical in the circumferential direction. If the characteristics are uniform in the circumferential direction, the inspection values can be represented by inspecting one row in the diameter direction, which is effective in improving the number of processing of the characteristic inspection.

Also in this embodiment, when a SiC single crystal epitaxial film is formed on one surface side of the wafer W in the process chamber 5, the characteristics of the epitaxial film reflect the temperature distribution derived from the susceptor shape. In the susceptor 10 of the present embodiment, the divided portion between the first susceptor 11 and the second susceptor 12 is outside the outer peripheral edge portion We of the wafer W.

Therefore, the first main body portion 21 of the first susceptor 11 arranged so as to face the other surface W2 side of the wafer W has no seams or protrusions. This makes it possible to improve the in-plane uniformity of the wafer temperature.

Further, the second protrusion 24 formed on the second susceptor 12 is formed at a position where the highest portion is lower than the surface of the cover member 26 (see FIG. 4B). Since a gap between the first susceptor 11 and the second susceptor 12 is formed outside the outer peripheral edge portion We of the wafer W, a notch or the like is not formed in the first main body portion 21 of the first susceptor 11. However, it is possible to prevent the wafer from floating due to the gas pool during epitaxial growth.

After forming the SiC single crystal epitaxial film on one surface side of the wafer W, the above-mentioned movement of the susceptor 10 is reversed, and the wafer W after the film formation is transferred to an external example cassette (for example, through the load lock chamber 3). It may be stored in (not shown).

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 embodiments, and various omissions, replacements, and changes can be made without departing from the gist of the invention. These embodiments and variations thereof are included in the scope of the invention described in the claims and the equivalent scope thereof, as are included in the scope and gist of the invention.

1 ... CVD device 2 ... Transfer chamber 3 ... Load lock chamber (carry-in / carry-out chamber)
5 ... Process chamber (deposition furnace)
10 ... Suceptor 11 ... 1st susceptor 12 ... 2nd susceptor 21 ... 1st main body 22, 22A, 22B, 22C ... 1st protrusion 23 ... 2nd main body 24, 24A, 24B, 24C ... 2nd protrusion 25, 25A , 25B, 25C ... Third protrusion H ... Robot hand W ... Wafer

Claims (10)

A susceptor that holds a wafer in a CVD device that forms a film on one side of a disk-shaped wafer by chemical vapor deposition.
The susceptor comprises a first susceptor and a second susceptor arranged so as to surround the first susceptor.
The first susceptor is formed with first protrusions that are in contact with each other at at least three or more of the outer peripheral edges on the other surface side of the wafer.
The second susceptor has a second protrusion that is in contact with the outer peripheral edge portion on the other surface side of the wafer at at least three places that are spaced apart from the first protrusion and that is in contact with the peripheral edge of the first susceptor. A susceptor characterized by being formed. The first aspect of the present invention is characterized in that the first susceptor has a disk-shaped first main body portion, and the first protrusion is erected upward from the peripheral edge of the first main body portion. The described susceptor. The susceptor according to claim 2, wherein the protrusion height of the first protrusion from one surface of the first main body portion is larger than the thickness of a plate-shaped wafer hand that introduces the wafer into the susceptor. .. The second susceptor has an annular plate-shaped second main body having an opening capable of accommodating the first main body of the first susceptor, and the second protrusion is the opening of the second main body. The susceptor according to claim 2 or 3, wherein the susceptor is projected from the edge portion of the surface toward the center portion. The susceptor according to claim 4, wherein the second susceptor has a third protrusion projecting downward from the second main body portion. The third projection of the second susceptor is characterized in that the height of protrusion from the other surface of the second main body portion is larger than the thickness of the plate-shaped wafer hand that introduces the wafer into the susceptor. Item 5. The susceptor according to item 5. The susceptor according to any one of claims 4 to 6, wherein a cover member is placed on one surface of the second main body of the second susceptor. Claim 1 is characterized in that the first protrusion and the second protrusion are alternately arranged at intervals of 60 ° from each other in an annular region overlapping the outer peripheral edge portion on the other surface side of the wafer. The susceptor according to any one of 7 to 7. The outer peripheral edge portion of the wafer is a ring-shaped region having a width of 10 mm or less from the peripheral edge toward the center with respect to the radius of the wafer, according to any one of claims 1 to 8. The described susceptor. A CVD apparatus comprising a film forming chamber having the susceptor according to any one of claims 1 to 9.

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