JP5669512B2 - Deposition system and support for film formation system - Google Patents

Description

  The present invention relates to a support table on which a wafer is placed when a film is grown on the surface of the wafer.

  Patent Document 1 discloses a support table on which a wafer is placed when a film is grown on the surface of the wafer. The support base includes a mounting member (outer susceptor) on which a wafer is mounted and a movable member (inner susceptor) that transports the wafer to the mounting member. The mounting member includes a support surface that comes into contact with the outer peripheral portion of the back surface of the wafer when the wafer is mounted. The movable member is movable between an upper position above the support surface and a lower position below the support surface. A convex portion is formed on the upper surface of the movable member. The end surface of the convex portion comes into contact with the inner peripheral portion (the portion on the inner peripheral side from the position where the support surface contacts) of the back surface of the wafer when the wafer is transferred. When placing a wafer on the support base, first, the movable member is moved to the upper position. Next, a wafer is placed on the movable member. At this time, the inner peripheral portion of the back surface of the wafer is supported by the convex portion. Next, the movable member is moved downward. When the movable member moves to a lower position (a position below the support surface), the outer peripheral portion of the back surface of the wafer is supported by the support surface of the mounting member, and the movable member is separated from the wafer. That is, the wafer is placed on the placement member. When taking out the wafer from the support after film formation, the movable member is moved to the upper position. Then, the wafer placed on the placement member is lifted by the movable member. When the movable member moves to the upper position, the wafer is carried out of the movable member by the transfer means.

  Patent Document 2 also discloses a support table on which a wafer is placed during film formation. The support base includes a mounting member (supporting area) on which the wafer is mounted and a movable member (lift ring) that transports the wafer to the mounting member. The mounting member includes a support surface that supports the wafer. The movable member is movable between an upper position above the support surface and a lower position below the support surface. The movable member includes three lift part pieces that contact the outer peripheral part of the back surface of the wafer and support the wafer when the wafer is transported, and a connecting part that connects the three lift part pieces. When placing a wafer on the support base, first, the movable member is moved to the upper position. Next, a wafer is placed on the movable member. At this time, the outer peripheral portion of the back surface of the wafer is supported by the lift piece. Next, the movable member is moved downward. When the movable member moves to a lower position (a position below the support surface), the wafer is supported on the support surface of the mounting member and the movable member is separated from the wafer. That is, the wafer is placed on the placement member. When the wafer is taken out from the support after film formation, the movable member is moved to the upper position to lift the wafer. Then, the wafer is carried out of the movable member by the transfer means.

JP 2009-070915 A JP 2000-138281 A

  In the support base of patent document 1, the convex part of a movable member is formed in the position which can contact the inner peripheral part of the back surface of a wafer. For this reason, when a wafer is mounted on the mounting member, a convex portion is positioned below the inner peripheral portion of the wafer. Therefore, the width of the gap between the inner peripheral portion of the wafer and the movable member is smaller at the portion where the convex portion is formed than at the portion where the convex portion is not formed. That is, only the convex portion of the support base is in a state of approaching the inner peripheral portion of the wafer. When the film is formed on the wafer, the wafer is heated. At this time, since the convex portion is partially close to the inner peripheral portion of the wafer, the temperature distribution in the wafer becomes non-uniform in the vicinity of the convex portion. When the temperature distribution becomes non-uniform in this way, the speed at which the film grows on the wafer differs between the vicinity of the convex portion and other portions. This difference in film formation rate hardly poses a problem when the film to be grown is thin. However, in recent years, a thick film having a film thickness of several μm or several tens of μm has been grown. In the case of growing a thick film, a difference in film thickness due to a difference in film formation rate occurs remarkably, resulting in a problem that a suitable film cannot be obtained.

  In the support base of Patent Document 2, the portion of the movable member that supports the wafer (that is, the lift piece) is formed at a position where it can contact the outer peripheral portion of the back surface of the wafer. For this reason, when the wafer is placed on the placement member, the lift piece is positioned below the outer peripheral portion of the wafer. For this reason, a non-uniform temperature distribution occurs in the outer peripheral portion of the wafer (in the vicinity of the lift piece) during film formation, but there is no particular problem because the outer peripheral portion of the wafer is a region where no semiconductor element is formed. However, in this support base, the connecting portion that connects the three lift pieces is formed at a position that is not covered by the wafer. For this reason, at the time of film formation, a film grows not only on the wafer but also on the connecting portion. Thus, even if a film grows on a part of the movable member, if the thickness of the film to be grown is thin, the problem does not occur so much. However, when the thick film described above is grown, the film may grow across the movable member and the mounting member. For this reason, when the movable member is subsequently moved, the film grown between the movable member and the mounting member is crushed and a large amount of particles are generated.

  The present specification provides a support base that can make the temperature distribution in the inner periphery of a semiconductor wafer more uniform during film formation and can prevent film growth on a movable member.

In the support table disclosed in this specification, a wafer is placed when a film is grown on the surface of the wafer. The support base includes a mounting member on which the wafer is mounted , and a movable member that is movable with respect to the mounting member and transports the wafer. The mounting member includes a through hole and a first support surface. The movable member is movable between a lower position housed in the through hole and an upper position above the lower position. The first support surface is formed around a region in which the movable member of the through hole is accommodated, and supports the wafer in contact with the outer peripheral portion of the back surface of the wafer when the wafer is placed. The movable member is formed on a second support surface that contacts the outer peripheral portion of the back surface of the wafer and supports the wafer when transporting the wafer, and an entire region on the inner peripheral side of the second support surface. 2 The upper surface located below a support surface is provided. The second support surface is located on the outer peripheral side than the inner peripheral end of the first supporting surface. At the top position, the second support surface is located above the first supporting surface, in the lower position, the second bearing surface you positioned below the same height or the first support surface and the first supporting surface. When the wafer supported on the first support surface is viewed in plan, the entire movable member is positioned within the range overlapping the wafer. The “inner peripheral end of the first support surface” means the end of the first support surface located on the inner peripheral side of the semiconductor wafer when the semiconductor wafer is supported by the first support surface. The “outer peripheral side” means the outer peripheral side of the semiconductor wafer when the semiconductor wafer is supported by the first support surface.

  When placing a wafer on the support base, first, the movable member is moved to the upper position. Next, a wafer is placed on the movable member. At this time, the outer peripheral portion of the back surface of the wafer is supported by the second support surface of the movable member. Next, the movable member is moved to the lower position. Then, the outer peripheral part of the back surface of the wafer is supported by the first support surface of the mounting member. Accordingly, the wafer is placed on the placement member, and the film formation process can be performed on the wafer placed on the placement member. When taking out the wafer from the support after film formation, the movable member is moved to the upper position. Then, the wafer placed on the placement member is lifted by the movable member. When the movable member moves to the upper position, the wafer is carried out of the movable member by the transfer means. In this support base, the second support surface of the movable member is positioned on the outer peripheral side with respect to the inner peripheral end of the first support surface of the mounting member. Therefore, in the state where the wafer is placed on the first support surface, the second support surface does not exist below the inner peripheral portion of the wafer. For this reason, it is suppressed that the temperature distribution of the inner peripheral portion of the wafer is disturbed by the second support surface during film formation. As described above, since the second support surface is positioned on the outer peripheral side with respect to the inner peripheral end of the first support surface, the influence of the second support surface on the temperature of the inner peripheral portion of the wafer can be reduced. . Therefore, according to this support base, it is possible to prevent the temperature distribution in the inner peripheral portion of the wafer from becoming nonuniform during film formation, and a thick film can be preferably grown. Further, in this support base, when the wafer supported on the first support surface is viewed in plan, the entire movable member is located within a range overlapping the wafer. That is, when the wafer is supported on the first support surface, the entire movable member is hidden behind the wafer. Therefore, it is possible to suppress the growth of the film on the movable member. For this reason, it can suppress that a film | membrane grows across a movable member and a mounting member.

The upper surface of the movable portion of the support described above is preferably a benzalkonium extend parallel to the rear surface of the wafer at a position spaced a distance from the rear surface of the wafer when the wafer is supported by the first supporting surface . The “inner peripheral side” means the inner peripheral side of the semiconductor wafer when the semiconductor wafer is supported by the first support surface.

  According to such a configuration, when the wafer is placed on the support table, the distance between the inner peripheral portion of the wafer and the support table is substantially constant. Therefore, the temperature distribution in the inner periphery of the wafer can be made more uniform during film formation.

  In the support base described above, it is preferable that the second support surface is an inclined surface that is displaced downward toward the inner peripheral side.

  According to such a configuration, the wafer can be supported more stably when the wafer is supported by the second support surface of the movable member.

  In addition, the present specification provides a film forming apparatus including any one of the above-described support bases and transport means. The transfer means includes a third support surface that supports the wafer in contact with the outer peripheral portion of the back surface of the wafer when the wafer is transferred. The transfer means transfers the wafer to and from the movable member in a mode in which the second support surface and the third support surface do not interfere when the movable member is at the upper position.

  According to such a configuration, the wafer can be delivered between the transfer means and the support base without contacting the inner periphery of the wafer.

1 is a longitudinal sectional view of a film forming apparatus 10 according to an embodiment. FIG. 3 is a top view of the wafer stage 20. The longitudinal cross-sectional view of the wafer stage 20 in the location (AA line of FIG. 2) in which the convex part 30 is not formed, and the location (BB line of FIG. 2) in which the convex part 30 is formed. 1 is a longitudinal sectional view of a film forming apparatus 10 according to an embodiment. The top view of the semiconductor wafer 70 mounted on the robot hand 90. FIG.

  The film forming apparatus 10 shown in FIG. 1 epitaxially grows a silicon film on the surface of a semiconductor wafer 70 made of silicon. As shown in FIG. 1, the film forming apparatus 10 includes a chamber 12. An exhaust pipe 14 is connected to the bottom surface of the chamber 12. The other end of the exhaust pipe 14 is connected to an exhaust pump (not shown). By operating the exhaust pump, the gas in the chamber 12 can be exhausted out of the chamber 12. A shower head 16 is installed at the top of the chamber 12. The shower head 16 includes a large number of injection holes communicating with the chamber 12. A raw material gas supply pipe 18 is connected to the shower head 16. A raw material gas which is a raw material of the silicon film is supplied from the raw material gas supply pipe 18 to the shower head 16. The shower head 16 injects the supplied source gas into the chamber 12 through the injection holes.

  A wafer stage 20 is installed in the chamber 12. A semiconductor wafer 70 is placed on the wafer stage 20 during film formation. The wafer stage 20 includes a susceptor 22 and a susceptor support member 24 that supports the susceptor 22. The susceptor support member 24 is a cylindrical member. A shaft portion 24 a having a small diameter is formed in the lower portion of the susceptor support member 24. A bearing portion 28 is formed at the bottom of the chamber 12. The shaft portion 24 a is inserted into the bearing portion 28. Accordingly, the susceptor support member 24 is attached to the chamber 12 so as to be rotatable around the central axis 24b. The susceptor support member 24 can be rotated by a driving device (not shown). The susceptor 22 is attached to the uppermost part of the susceptor support member 24. The susceptor 22 rotates with the susceptor support member 24.

  As shown in FIGS. 1 and 2, the susceptor 22 includes an inner susceptor 30 and an outer susceptor 40. As shown in FIG. 2, when the wafer stage 20 is viewed from above, the inner susceptor 30 and the outer susceptor 40 have a substantially circular outer shape. However, the inner susceptor 30 is formed with three convex portions 32 protruding from the circular portion to the outer peripheral side. The central axis of the inner susceptor 30 and the central axis of the outer susceptor 40 substantially coincide with the central axis 24 b of the susceptor support member 24. The three convex portions 32 are arranged at predetermined equiangular intervals around the central axis 24b. The outer susceptor 40 is formed with a through hole 48 that communicates from the upper surface to the lower surface of the outer susceptor 40 along the central axis 24b. The inner susceptor 30 is disposed in the through hole 48 of the outer susceptor 40.

  As shown in FIG. 3A, the inner surface of the through hole 48 of the outer susceptor 40 is formed in a stepped shape in the portion where the convex portion 32 is not formed. By this step, the outer susceptor 40 is formed with an outer peripheral wall 42, a wafer support surface 44, and an inner susceptor support surface 46. The outer peripheral wall 42 is formed on the outermost peripheral portion of the outer susceptor 40 and protrudes upward from the wafer support surface 44. The wafer support surface 44 is formed on the inner peripheral side of the outer peripheral wall 42. The wafer support surface 44 is a plane that extends substantially horizontally, and supports the semiconductor wafer 70 when the semiconductor wafer 70 is placed on the outer susceptor 40. The inner susceptor support surface 46 is formed on the inner peripheral side of the wafer support surface 44. The inner susceptor support surface 46 is located below the wafer support surface 44. Moreover, as shown in FIG.3 (b), in the part in which the convex part 32 is formed, the expansion support surface 46a which expanded the inner side susceptor support surface 46 to the outer peripheral side is formed.

  As shown in FIG. 3, the inner susceptor 30 is accommodated in the through hole 48 and placed on the inner susceptor support surface 46. The outer shape of the inner susceptor 30 is formed in a shape along the through hole 48. Each convex part 32 is arrange | positioned on the expansion support surface 46a. The upper surface 34 of each convex portion 32 protrudes above the upper surface 36 of the other part of the inner susceptor 30. The upper surface 34 of each convex portion 32 is a wafer support surface that supports the semiconductor wafer 70 when the semiconductor wafer 70 is transported by the inner susceptor 30. As shown in FIGS. 3A and 3B, the inner peripheral end 34 a of the wafer support surface 34 is located on the outer peripheral side with respect to the inner peripheral end 44 a of the wafer support surface 44. Further, the outer peripheral end 34 b of the wafer support surface 34 is located on the inner peripheral side of the outer peripheral end 70 a of the semiconductor wafer 70 when the semiconductor wafer 70 is placed on the wafer support surface 44. That is, the entire wafer support surface 34 is located within the range of the width W shown in FIG. Since the outer peripheral end 34 b of the wafer support surface 34 is located on the inner peripheral side with respect to the outer peripheral end 70 a of the semiconductor wafer 70 placed on the wafer support surface 44, when the semiconductor wafer 70 is viewed in plan, the inner susceptor 30. The whole overlaps with the semiconductor wafer 70. The wafer support surface 34 is slightly inclined so as to be displaced downward toward the inner peripheral end 34a from the outer peripheral end 34b. The outer peripheral edge 34 b (the uppermost portion) of the wafer support surface 34 is positioned slightly below the wafer support surface 44. The upper surface 36 of the inner susceptor 30 (the upper surface of the portion excluding the wafer support surface 34 of the convex portion 32) is formed in a substantially horizontal plane.

  As shown in FIG. 1, an internal space 50 is formed in the wafer stage 20. The internal space 50 is formed below the susceptor 22. A heater 52 and a plurality of lift pins 54 are installed in the internal space 50. The heater 52 heats the semiconductor wafer 70 placed on the susceptor 22 via the susceptor 22. Each lift pin 54 can move upward from the position shown in FIG. When each lift pin 54 moves upward, the tip of each lift pin 54 comes into contact with the back surface of the inner susceptor 30. Each lift pin 54 is installed in a number that can stably support the inner susceptor 30. Therefore, when each lift pin 54 moves further upward from a position where it abuts against the inner susceptor 30, the inner susceptor 30 is lifted from the outer susceptor 40 by each lift pin 54 as shown in FIG. 4. As a result, the semiconductor wafer 70 can be transferred upward. In this state, the outer peripheral portion of the semiconductor wafer 70 is supported by the wafer support surface 34 of the inner susceptor 30.

  Next, the operation of the film forming apparatus 10 will be described. First, the operation of the film forming apparatus 10 when the semiconductor wafer 70 is placed on the wafer stage 20 will be described. When placing the semiconductor wafer 70 on the wafer stage 20, first, the semiconductor wafer 70 is carried into the chamber 12 by the robot hand. At this time, as shown in FIG. 5, the robot hand 90 supports the semiconductor wafer 70 by partially contacting the outer peripheral portion of the back surface of the semiconductor wafer 70. The robot hand 90 moves the semiconductor wafer 70 to a position directly above the wafer stage 20. FIG. 5 shows a horizontal positional relationship between the inner susceptor 30 and the robot hand 90 when the semiconductor wafer 70 is moved immediately above the wafer stage 20. As illustrated, the inner susceptor 30 is disposed so as to overlap the semiconductor wafer 70. The robot hand 90 and the inner susceptor 30 are arranged so as not to overlap each other.

  Next, the lift pin 54 moves upward, and the inner susceptor 30 is lifted from the outer susceptor 40. As shown in FIG. 4, the inner susceptor 30 is lifted above the robot hand 90. As a result, the semiconductor wafer 70 is lifted by the inner susceptor 30, and the semiconductor wafer 70 is separated from the robot hand 90. At this time, the three wafer support surfaces 34 of the inner susceptor 30 come into contact with the semiconductor wafer 70. Each wafer support surface 34 is in contact with the outer peripheral portion of the back surface of the semiconductor wafer 70. As a result, the semiconductor wafer 70 is supported. As shown in FIG. 5, the robot hand 90 is arranged so as not to overlap the inner susceptor 30, so that the robot hand 90 and the inner susceptor 30 do not interfere with each other. Further, since the wafer support surface 34 protrudes above the upper surface 36 of the inner susceptor 30, a minute gap is formed between the upper surface 36 of the inner susceptor 30 and the semiconductor wafer 70. That is, the upper surface 36 of the inner susceptor 30 does not contact the semiconductor wafer 70. In general, when a semiconductor wafer is placed on a plane, an air layer is formed between the semiconductor wafer and the plane, and the semiconductor wafer slides sideways. Since the inner susceptor 30 is in contact with the semiconductor wafer 70 only at the three wafer support surfaces 34, the side slip of the semiconductor wafer 70 is suppressed. Further, as described above, the three wafer support surfaces 34 are inclined so as to be displaced downward toward the inner peripheral side. Also by this, the side slip of the semiconductor wafer 70 is suppressed. When the inner susceptor 30 lifts the semiconductor wafer 70, the robot hand 90 is retracted in the direction indicated by the arrow in FIG. Next, the lift pin 54 is lowered to the original position, and the inner susceptor 30 is lowered to the position shown in FIG. As shown in FIG. 3, the diameter of the semiconductor wafer 70 is smaller than the inner diameter of the outer peripheral wall 42 of the outer susceptor 40 and larger than the inner diameter of the wafer support surface 44 (the diameter of a circle drawn by the inner peripheral end 44a). Therefore, when the inner susceptor 30 is lowered to the position shown in FIG. 1, the semiconductor wafer 70 is placed on the wafer support surface 44. At this time, the outer peripheral portion of the back surface of the semiconductor wafer 70 is in contact with the wafer support surface 44. Further, as shown in FIG. 3B, the wafer support surface 34 of the inner susceptor 30 is positioned below the wafer support surface 44 of the outer susceptor 40, so that the inner susceptor 30 is not in contact with the semiconductor wafer 70. It becomes.

  Next, the operation of the film forming apparatus 10 during film formation will be described. At the time of film formation, the gas in the chamber 12 is discharged out of the chamber 12 through the exhaust pipe 14, and the source gas is supplied from the shower head 16 into the chamber 12. The supplied source gas flows into the exhaust pipe 14 through the chamber 12. Further, the wafer stage 20 is rotated around the central axis 24b by a driving device (not shown). As a result, the source gas in the chamber 12 flows along the surface of the semiconductor wafer 70. In addition, the semiconductor wafer 70 is heated by the heater 52. As a result, the source gas reacts on the surface of the semiconductor wafer 70, and a film grows epitaxially on the surface of the semiconductor wafer 70.

  An upper surface 36 of the inner susceptor 30 positioned below the wafer support surface 44 is formed in the entire region on the inner peripheral side of the wafer support surface 44 in the upper surface of the wafer stage 20. When the semiconductor wafer 70 is placed on the wafer support surface 44, only the outer peripheral portion of the back surface of the semiconductor wafer 70 is in contact with the wafer support surface 44, and the inner peripheral portion of the back surface of the semiconductor wafer 70 is not in contact with the wafer stage 20. . The upper surface 36 of the inner susceptor 30 is a substantially horizontal plane. Therefore, when the semiconductor wafer 70 is placed on the wafer support surface 44, a gap having a substantially constant width is formed between the inner peripheral portion of the back surface of the semiconductor wafer 70 and the upper surface 36 of the inner susceptor 30. . As described above, since the distance between the inner peripheral portion of the back surface of the semiconductor wafer 70 and the upper surface 36 of the inner susceptor 30 is constant, the inner peripheral portion of the semiconductor wafer 70 can be uniformly heated. Therefore, a film can be uniformly grown on the upper surface of the inner peripheral portion of the semiconductor wafer 70 on which the semiconductor elements are formed. Therefore, according to the film forming apparatus 10, a high-quality thick film with few defects can be formed. In addition, the outer peripheral portion of the back surface of the semiconductor wafer 70 is in contact with the wafer support surface 44 over substantially the entire periphery, but is not in contact with the wafer support surface 34 at locations on the convex portion 32 of the inner susceptor 30. It has become. Accordingly, the temperature distribution of the semiconductor wafer 70 on the convex portion 32 may be non-uniform, and the thickness of the film grown on the surface of the semiconductor wafer 70 on the convex portion 32 may be non-uniform. However, since no semiconductor element is formed on the outer periphery of the semiconductor wafer 70, there is no problem due to the non-uniform film thickness. Further, the wafer support surface 34 of the inner susceptor 30 is positioned below the wafer support surface 44 of the outer susceptor 40, but the difference in vertical position between the wafer support surface 34 and the wafer support surface 44 is slight. is there. Therefore, the temperature distribution is not so uneven even at the outer periphery of the semiconductor wafer 70.

  In addition, a film grows on the wafer stage 20 at the time of film formation. When a film grows between the outer susceptor 40 and the inner susceptor 30, a particle problem or the like occurs. However, in the film forming apparatus 10, the entire inner susceptor 30 is positioned below the semiconductor wafer 70 in a state where the semiconductor wafer 70 is placed on the outer susceptor 40. That is, the entire inner susceptor 30 is covered by the semiconductor wafer 70. For this reason, the film growth on the surface of the inner susceptor 30 is suppressed. Therefore, in this film forming apparatus 10, it is possible to suppress a film from growing between the outer susceptor 40 and the inner susceptor 30.

  Further, the outer peripheral portion of the back surface of the semiconductor wafer 70 is in contact with the wafer support surface 44 in substantially the entire periphery except for the portion where the convex portion 32 is formed. As a result, the raw material gas is prevented from flowing into the back surface side of the semiconductor wafer 70.

  Next, an operation when the semiconductor wafer 70 is unloaded from the chamber 12 after film formation will be described. When unloading the semiconductor wafer 70, the lift pins 54 are raised to the position shown in FIG. 4 to lift the inner susceptor 30 and the semiconductor wafer 70. Next, the robot hand 90 is moved to the position shown in FIG. 4 and the lift pins 54 are lowered. As a result, the semiconductor wafer 70 is placed on the robot hand 90. Next, the semiconductor wafer 70 is carried out of the chamber 12 by the robot hand 90. Further, the lift pin 54 is lowered to a position where the inner susceptor 30 is accommodated in the outer susceptor 40 as shown in FIG.

  As described above, according to the film forming apparatus 10 of the embodiment, a thick film can be preferably grown.

  In the embodiment described above, the wafer support surface 34 is positioned below the wafer support surface 44, but the wafer support surface 34 may be formed at the same height as the wafer support surface 44. According to such a configuration, when the semiconductor wafer 70 is placed on the wafer support surface 44, the wafer support surface 34 comes into contact with the semiconductor wafer 70. For this reason, the temperature distribution in the outer peripheral portion of the semiconductor wafer 70 can be made more uniform, and the raw material gas can be further suppressed from entering the back side of the semiconductor wafer 70.

Specific examples of the present invention have been described in detail above, but these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes of the specific examples illustrated above.
The technical elements described in this specification or the drawings exhibit technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the technology illustrated in the present specification or the drawings achieves a plurality of objects at the same time, and has technical utility by achieving one of the objects.

DESCRIPTION OF SYMBOLS 10: Film-forming apparatus 12: Chamber 14: Exhaust pipe 16: Shower head 18: Source gas supply pipe 20: Wafer stage 22: Susceptor 24: Susceptor support member 30: Inner susceptor 32: Convex part 34: Wafer support surface 40: Outer Susceptor 42: Outer peripheral wall 44: Wafer support surface 46: Inner susceptor support surface 48: Through hole 52: Heater 54: Lift pin 70: Semiconductor wafer 90: Robot hand

Claims (4)

A support table on which a wafer is placed when a film is grown on the surface of the wafer;
A mounting member on which the wafer is mounted; a movable member that is movable with respect to the mounting member and that transports the wafer;
The mounting member includes a through hole and a first support surface,
The movable member is movable between a lower position housed in the through hole and an upper position above the lower position,
The first support surface is formed around a region where the movable member of the through hole is accommodated, and supports the wafer in contact with the outer peripheral portion of the back surface of the wafer when the wafer is placed.
The movable member is formed on a second support surface that contacts the outer peripheral portion of the back surface of the wafer and supports the wafer when transporting the wafer, and an entire region on the inner peripheral side of the second support surface. 2 It has an upper surface located below the support surface ,
The second support surface is located on the outer peripheral side of the inner peripheral end of the first support surface,
In the upper position, the second support surface is located above the first support surface, and in the lower position, the second support surface is located at the same height as the first support surface or below the first support surface ,
When the wafer supported by the first support surface is viewed in plan, the entire movable member is located within a range overlapping with the wafer.
A support stand characterized by that. It said movable member upper surface, claim wafer and wherein the benzalkonium extend parallel to the rear surface of the wafer at a position spaced a distance from the rear surface of the wafer when it is supported on the first supporting surface 1 The support stand as described in.   The support base according to claim 1, wherein the second support surface is an inclined surface that is displaced downward toward the inner peripheral side. A film forming apparatus comprising the support table according to any one of claims 1 to 3 and a transfer means for transferring a wafer,
The transfer means includes a third support surface that supports the wafer in contact with the outer peripheral portion of the back surface of the wafer when transferring the wafer,
The film forming apparatus, wherein the transfer means delivers the wafer to and from the movable member in a mode in which the second support surface and the third support surface do not interfere when the movable member is at the upper position.

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