JP2010239023A - Substrate transfer device, and substrate processing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a substrate transfer device which hardly causes a position shift of a substrate during transfer and is capable of suppressing production of particles, and to provide a substrate processing device provided with the same. <P>SOLUTION: The substrate transfer device is equipped with a holding member 10 that is capable of holding and horizontally moving a substrate W, wherein the holding member 10 has a plurality of holding surfaces 13, 14 which have a concave surface with an arc-shaped cross section in the vertical direction and which are provided along the periphery of the substrate W mounting areas in order to hold the periphery on the bottom surface side of the substrate W. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a substrate transport apparatus that transports a substrate during substrate processing and a substrate processing apparatus including the substrate, and more particularly to a technique for transporting a substrate in a vacuum atmosphere where it is difficult to apply a vacuum chuck or the like.

  In the manufacturing process of a semiconductor device, for example, CVD (Chemical Vapor Deposition) or the like is performed by supplying a source gas in a vacuum atmosphere to the surface of a heated semiconductor wafer (hereinafter referred to as a wafer) and forming a film on the surface of the wafer. For the purpose of increasing the in-plane uniformity of the film thickness, etc., a single-wafer type substrate processing apparatus is used in which wafers are carried into a vacuum container one by one and then heat treatment is performed.

  In a single-wafer type substrate processing apparatus, a plurality of processing modules composed of vacuum containers or the like are connected to a common transfer chamber, and the transfer chamber is used as a vacuum atmosphere to transfer wafers between each processing module and the outside. There are types called multi-chambers, cluster tools, etc. that have improved throughput.

  A wafer transfer device having a holding member is provided in the transfer chamber of the multi-chamber, and the wafer is transferred between each processing module and the outside through the transfer chamber while being held by the holding member. . Since this holding member conveys the wafer in a vacuum atmosphere, it is difficult to fix the wafer by a vacuum chuck or the like, and it is necessary to quickly transfer the wafer to and from the processing module. It is also not realistic to provide For this reason, for example, a fork-shaped ceramic holding member is provided with a plurality of wafer support portions made of, for example, flat small discs, and a wafer is simply placed on these wafer support portions. There is a holding member of a type that conveys a wafer in a state.

  On the other hand, the multi-chamber type substrate processing apparatus is required to further improve the throughput, and accordingly, the wafer needs to be transferred at a higher speed. At this time, at the time of acceleration when the holding member starts to move or at the time of deceleration when it stops, the wafer is subjected to a horizontal inertial force, and the inertial force applied to the wafer by increasing the transfer speed is likely to be larger than before. . However, as described above, with a holding member that simply mounts the wafer on the wafer support, there is only a frictional force acting between the wafer and the wafer support so that the wafer can be displaced. In some cases, the wafer may fall. For this reason, the wafer transfer speed cannot be increased to the required speed, which may be a limitation on throughput improvement.For example, acceleration is performed along a predetermined speed curve so that a sudden inertia force is not applied to the wafer. Advanced acceleration control such as executing deceleration must be performed, which may complicate the device configuration.

  For example, Japanese Patent Application Laid-Open No. H10-228688 discloses a set of a regulating member having a horizontal plane and a vertical plane orthogonal to each other and an inclined member having an inclined surface, and for example, the regulating member and the inclined surface sandwiching the center of the wafer. Two sets are arranged facing each other, and the horizontal displacement of the wafer is regulated by the vertical surface on the regulating member side of each set and the inclined surface of the inclined member, while the horizontal surface of the regulating member and the inclined surface of the inclined member are regulated. A holding member that positions the wafer by supporting the wafer from the lower surface side is described. In addition, Patent Document 2 describes a holding member that supports a bottom surface of a wafer and includes a substrate support block having a side wall surface that is curved along the outer surface of the wafer in order to perform horizontal positioning of the wafer. Yes. Furthermore, in Patent Document 3, for example, wafer holding members that protrude in a mountain shape are provided at four locations, the wafer is held by the inclined surface of the mountain wafer holding member, and the wafer is pressed from the bottom surface side and the outer peripheral direction. A holding member that makes it difficult for the wafer to shift is described.

JP 2003-282670 A: 0036 paragraph, 0039 paragraph to 0043 paragraph, FIGS. 5 and 6 JP 2005-123642 A: 0020 paragraph, 0053 paragraph, FIG. JP 2000-3951 A: paragraph 0019, FIG.

  In the holding members described in Patent Documents 1 to 3, the bottom surface of the wafer is a horizontal surface (horizontal surface of the regulating member of Patent Document 1, the holding member body of Patent Document 2) or an inclined surface (the inclined member of Patent Document 1). While supporting the wafer by supporting it with the wafer holding member of Patent Document 3, the surface (vertical surface of the restricting member of Patent Document 1, the side wall surface of Patent Document 2) or the inclined surface (Patent Document 1) The wafer is prevented from being displaced in the horizontal direction during acceleration and deceleration by pressing the wafer from the outside with an inclined member (wafer holding member of Patent Document 3).

  Here, for example, on the wafer formed by the above-described CVD, a film is also formed on, for example, the peripheral edge or the side peripheral surface of the wafer, and when this part comes into contact with the holding member, the film is scraped and causes the generation of particles. Therefore, the contact portion between the wafer and the holding member is preferably as small as possible. However, in the holding member that supports the wafer from the bottom surface side described in Patent Document 1 and Patent Document 2 and suppresses the wafer shift on the surface extending in the vertical direction, when attention is paid to the member holding the wafer, the holding member and the wafer Is a premise to contact at least two places, and there are many contact places, and there is a high possibility that particles are generated here.

  On the other hand, in the holding member that supports the wafer with the inclined surface described in Patent Document 1 or Patent Document 3, the number of contact points with the wafer is smaller than the holding member that holds the bottom surface and the side surface. However, the wafer is provided with a region having an inclined surface called a bevel portion, and the shape of the bevel portion varies from wafer to wafer within a tolerance. For this reason, in a wafer in which a bevel portion having an inclination close to the inclined surface of the holding member that supports the wafer is formed, the contact area between the inclined surface and the bevel portion may be increased, and particles may be easily generated. Further, even when the wafer is warped during the manufacturing process of the semiconductor device, the contact area between the inclined surface and the bevel portion may increase.

  In addition to the above, in the holding member described in Patent Document 3, it is difficult to secure the processing accuracy of chamfering and positioning because it is difficult to form the wafer holding member protruding in a chevron shape with ceramics. Made of elastomer. However, the elastomer is softer than the wafer, and in this case, the wafer holding member side may be scraped to generate particles. In addition, when CVD is performed on a wafer, since the process temperature is high, a holder made of elastomer having low heat resistance may not be used.

  The present invention has been made under such circumstances, and an object of the present invention is to provide a substrate transport device that is less likely to be displaced during transport and suppresses generation of particles, and the substrate transport device. It is to provide a substrate processing apparatus.

A substrate transport apparatus according to the present invention includes a holding member that holds a substrate and is movable in a horizontal direction;
In order to hold the peripheral portion on the lower surface side of the substrate, the holding member is provided with a plurality of holding surfaces along the circumferential direction of the mounting region of the substrate, and a holding surface whose vertical section is an arc-shaped concave curved surface It is characterized by that.

The substrate transfer device may have the following features.
(A) The holding member holds the substrate by supporting, on the holding surface, a ridge line where a bottom surface of the substrate, which is a circular substrate having a bevel portion formed on a peripheral portion, and an inclined surface of the bevel portion intersect. To do.
(B) The holding member is formed in a fork shape extending in a plurality of branches from the base end portion to the tip side, and the holding surface is formed at each branch portion, and the horizontally long holding surface is formed at the base end portion. is being done.
(C) The holding member is made of ceramic.

Further, a substrate processing apparatus according to another invention includes a processing module for performing a heat treatment on a substrate in a vacuum atmosphere,
A transfer chamber that is hermetically connected to the processing module and carries the substrate in and out of the processing module in a vacuum atmosphere;
And the above-described substrate transfer devices provided in the transfer chamber.

  According to the present invention, the shape of the holding surface for holding the substrate provided on the holding member is formed so that the vertical cross-section is an arc-shaped concave curved surface. By supporting the peripheral edge of the substrate, a horizontal force from the concave curved surface toward the center of the substrate acts on the substrate, and resists the inertial force that acts when accelerating or decelerating the substrate. The occurrence of misalignment can be suppressed. Furthermore, even when the substrate shape varies or when the substrate is warped, the area of the contact portion between the substrate and the holding member is kept small, and generation of particles can be suppressed.

It is a top view of the film-forming apparatus which concerns on embodiment of this invention. It is a perspective view which shows the structure of the holding arm provided in the 2nd conveyance chamber of the said film-forming apparatus. It is the top view and side view which show the structure of the wafer holding member provided in the front-end | tip part of the said holding arm. It is a perspective view which shows the state which hold | maintained the wafer with the said wafer holding member. It is explanatory drawing which shows the state holding the wafer with the said wafer holding member. It is an enlarged view which shows the contact state of the holding surface of the said wafer holding member, and a wafer. It is an enlarged view which shows the contact state of the said holding surface and wafer when a wafer shape varies. It is explanatory drawing which shows a mode that the wafer of the inclined state is hold | maintained with the said wafer holding member. It is an enlarged view which shows the contact state of the holding surface of the said wafer holding member, and the wafer of the inclined state. It is explanatory drawing which shows a mode that the wafer of the state which the curvature which the center part protruded upwards generate | occur | produced in the said wafer holding member was hold | maintained. It is an enlarged view which shows the contact state of the wafer of the state which curved the holding surface of the said wafer holding member, and the upper direction. It is explanatory drawing which shows a mode that the wafer of the state which the curvature which the center part protrudes in the downward direction generate | occur | produced in the said wafer holding member was hold | maintained. It is an enlarged view which shows the contact state of the wafer of the state which curved the holding surface of the said wafer holding member, and the downward direction. It is a perspective view which shows the structure of the said wafer holding member which concerns on a comparative example.

  Hereinafter, a substrate transport apparatus according to an embodiment of the present invention and a substrate processing apparatus including the same will be described by taking a multi-chamber type film forming apparatus 2 as an example. FIG. 1 is a plan view of a film forming apparatus 2 according to the present embodiment. The film forming apparatus 2 includes, for example, three mounting tables 21 on which a FOUP 4 storing a predetermined number of wafers W to be processed is mounted, and a first transfer chamber 22 that transfers the wafer W taken out of the FOUP 4 in an air atmosphere. For example, two load lock chambers 25 arranged side by side on the left and right sides for switching the chamber between an air atmosphere and a vacuum atmosphere to wait for the wafer W, and a second transfer chamber for transferring the wafer W in a vacuum atmosphere 26 and, for example, four vacuum vessels 28a to 28d for performing a film forming process on the loaded wafer W. These devices are arranged in the order of the mounting table 21, the first transfer chamber 22, the load lock chamber 25, the second transfer chamber 26, and the vacuum containers 28 a to 28 d with respect to the loading direction of the wafer W. The matching devices are connected in an airtight manner through the open / close door 221 and the gate valves G1 to G3. In the following description, the direction in which the mounting table 21 is provided will be described as the front side.

  On the side wall surface of the first transfer chamber 22, an opening / closing door 221 is provided corresponding to each FOUP 4 mounted on the mounting table 21. Each open / close door 221 is configured to be movable up and down between a position facing the FOUP 4 and a retracted position on the lower side thereof, and a lid provided on a side surface of the FOUP 4 is opened and closed during the lifting operation. The wafer W can be taken out and stored between the first transfer chamber 22 and the FOUP 4.

  The first transfer chamber 22 is a transfer device that is movable in the left-right direction along rotation, expansion and contraction, and travel track 232 for taking out and transferring the wafers W from the FOUP 4 one by one in the first transfer chamber 22. A device 23 is installed. The first transfer device 23 includes, for example, holding arms 231a and 231b made of two SCARA-type multi-joint arms, and these holding arms 231a and 231b are the FOUPs 4, alignment chambers 24 and load lock chambers described later. The wafer W can be transferred between 25. As shown in FIG. 1, each holding arm 231a, 231b is provided with a fork-shaped wafer holding member divided into two forks, and a vacuum chuck (not shown) is provided on the contact surface of these wafer holding members with the wafer W. Even when the wafer W is transferred at a high speed, the wafer W can be fixed and held against the inertial force acting during acceleration and deceleration.

  An alignment chamber 24 for aligning the wafer W is provided, for example, on the side wall surface of the left hand as viewed from the front side of the first transfer chamber 22. In the alignment chamber 24, for example, an orienter 241 including an optical sensor for detecting notches and orientation flats provided on the wafer W and a turntable for performing alignment of the wafer W is provided. Before the wafer W taken out from the FOUP 4 is transferred to the load lock chamber 25, alignment for adjusting the orientation of the wafer W in a predetermined direction can be executed.

  The ceiling portion of the first transfer chamber 22 is provided with a fan filter unit (not shown) composed of a fan that sends air into the room and a filter that cleans the air, and a floor portion that faces this is not shown. By providing this exhaust unit, a descending air flow of clean air is formed in the first transfer chamber 22.

  In the rear stage of the first transfer chamber 22, two load lock chambers 25 are provided on the left and right via gate valves G 1, respectively. Each load lock chamber 25 includes a stage 251 for placing a wafer W thereon. In addition, a vacuum pump and a leak valve (not shown) for switching the inside of the load lock chamber 25 between an air atmosphere and a vacuum atmosphere are connected.

  These two load lock chambers 25 are connected to a common second transfer chamber 26 via a gate valve G2. As shown in FIG. 1, the load lock chamber 25 is configured as a casing having a hexagonal shape, for example, and the side wall surfaces forming the two sides on the front side of the hexagon are connected to the load lock chamber 25 described above. On the other hand, vacuum vessels 28a to 28d in which a film forming process, which is a heat treatment, is performed on the wafer W are connected to the remaining four side walls. In the second transfer chamber 26, the substrate transfer of the present invention configured to be rotatable and extendable to transfer the wafer W in a vacuum atmosphere between the load lock chamber 25 and each of the vacuum containers 28a to 28d. A second transfer device 27, which is a device, is installed, and the second transfer chamber 26 is connected to a vacuum pump (not shown) for keeping the inside of the second transfer chamber 26 in a vacuum atmosphere.

  Each of the vacuum vessels 28a to 28d includes, for example, a stage 281 provided with a heat source for heating the wafer W and a gas supply mechanism (not shown) to which process gas is supplied. In addition, it is connected to a vacuum pump (not shown), and is configured as a processing module that performs a heat treatment performed in a vacuum atmosphere, for example, a film forming process by thermal CVD using a film forming gas or ALD (Atomic Layer Deposition). . In each of the vacuum vessels 28a to 28d, in addition to the film forming process described above, an etching process using an etching gas or an ashing process using an ashing gas may be performed, and the contents of the process performed in these vacuum containers 28a to 28d May be the same as each other or may be configured to perform different processes.

  In the film forming apparatus 2 having the configuration described above, the second transfer device 27 provided in the second transfer chamber 26 transfers the wafer W at a high speed in a vacuum atmosphere to which a vacuum chuck is difficult to apply. Even if the wafer W is not easily displaced or dropped, and even when the wafer W is uneven or warped, the area of the contact portion with the wafer W is kept small, and particles are generated. It is the structure which can suppress. The detailed configuration will be described below.

  The second transfer device 27 includes, for example, two holding arms 1a and 1b, and each holding arm 1a and 1b includes, for example, a swing arm portion 18, a middle arm portion 17, and a support arm portion as shown in FIG. 16 are configured as SCARA-type articulated arms connected to each other in this order from the base end side via a rotating shaft (not shown). The base end side of the swing arm portion 18 is pivotally connected to the main body of the second transfer device 27 via the swing shaft 19, while the front end portion of the support arm portion 16 holds the wafer W. A wafer holding member 10 which is a holding member is fixed.

  In addition, a rotating shaft for extending and retracting the arm portions 16 to 18 is provided in the turning shaft 19. The rotating shaft is rotated by a motor to be provided at a joint portion of each arm portion 16 to 18. The pulled pulley rotates through the belt, and the wafer holding member 10 can be linearly moved in the horizontal direction. Although these rotating shafts, motors, pulleys and the like are not shown, they constitute an advance / retreat mechanism for moving the wafer holding member 10 back and forth. Further, in the second transfer device 27 having these two holding arms 1a and 1b, the second transfer device 27 itself rotates around the vertical axis in the second transfer chamber 26 as shown in FIG. Can do.

  FIGS. 3A and 3B are a plan view and a side view of the wafer holding member 10 according to the present embodiment provided at the tip of the holding arms 1a and 1b as viewed from the upper surface side. The wafer holding member 10 has, for example, a base end member 11 made of a flat member that extends left and right when viewed from the support arm portion 16 side shown in FIG. A fork-shaped appearance is formed integrally with a support member 12 that is a flat and elongated branch portion that is a plurality of, for example, two branches extending from the end portion toward the front end portion. It is configured as a member. The wafer holding member 10 is formed by, for example, cutting a ceramic sintered body such as alumina.

As shown in the side view of FIG. 3B, each of the two support members 12 has a base end portion connected to the base end member 11 and a thickness “h ₁ ” of the front end portion of about 4 mm. The thickness “h ₂ ” of the region sandwiched between the end portion and the tip portion is, for example, about 2 mm, and the boundary between the regions having different thicknesses is continuously connected by a concave curved surface. The concave curved surfaces are the holding surfaces 13 and 14 of the wafer W.

  Hereinafter, when the holding surface on the base end side is referred to as the base end holding surface 13 and the holding surface on the tip end side is referred to as the tip holding surface 14, the base end holding surface 13 is 2 as shown in FIG. The base end member 11 is formed on the base end member 11 as a horizontally long continuous surface extending over a region between the support members 12. When viewed from the top surface side, the continuous surface supports, for example, a wafer W having a diameter of 300 mm from the bottom surface side. It has an elongated arc shape obtained by cutting off a part of the annular region S that can be formed. On the other hand, each of the distal end holding surfaces 14 provided at the distal end portion of the support member 12 that is a bifurcated portion is also an annular shape common to the arc-shaped region on the proximal end holding surface 13 side. It is formed in a short arc shape obtained by cutting a part of the region S. Further, the thick portion formed along the base end side holding surface 13 in the outer peripheral region of the base end side holding surface 13 is a rib 15 for maintaining the strength of the wafer holding member 10.

  By providing the above-described configuration, the wafer holding member 10 holds the wafer W in a state where it is supported from the bottom side by the base end side holding surface 13 and the tip end side holding surface 14 as shown in the perspective view of FIG. The wafer W can be transferred in the second transfer chamber 26 by operating the scalar holding arms 1a and 1b in this state. In other words, the wafer holding member 10 is provided with a plurality of holding surfaces 13 and 14 along the circumferential direction of the mounting area of the wafer W. Here, the concave curved surfaces constituting the proximal end holding surface 13 and the distal end holding surface 14 have the characteristics described below, thereby suppressing misalignment during transfer of the wafer W and reducing the contact area with the wafer W. It has a structure.

  As schematically shown in FIG. 5, the concave curved surfaces of the holding surfaces 13 and 14 formed on the base end member 11 and the support member 12 of the wafer holding member 10 are spheres having a distance R from the center O of about 390 mm, for example. It is comprised as a part of inner surface, and the cross section of the perpendicular direction of the said concave curved surface is circular arc shape. Further, these concave curved surfaces have a curvature capable of supporting a ridge line where the bottom surface of the wafer W and the inclined surface of the bevel portion intersect when the wafer W is placed on the wafer holding member 10 horizontally, for example.

Further, when it is noted in detail the shape of these concave surface, the concave surface height H of about 2mm as shown in FIG. 5, the opening diameter _{L 1} of about 305mm of the holding surface 13 and 14, the holding surface 13, 14 diameter L ₂ of the bottom side is 295mm in, is formed along the area S of the aforementioned annular shown in FIG. 3, the wafer W during the mounting standing time and transported as shown in FIG. 8 Even when tilted, the holding surfaces 13 and 14 can support the wafer W.

  Returning to the description of the film forming apparatus 2 as a whole, the film forming apparatus 2 includes a control unit 3 as shown in FIG. The control unit 3 includes, for example, a computer having a CPU and a storage unit (not shown). The storage unit operates the film forming apparatus 2, that is, takes out the wafer W from the FOUP 4 mounted on the mounting table 21. A program in which a group of steps (commands) related to the operation until the wafer W is stored in the FOUP 4 after being carried into the vacuum containers 28a to 28d and subjected to heat treatment such as CVD or ALD is recorded. ing. This program is stored in a storage medium such as a hard disk, a compact disk, a magnetic optical disk, or a memory card, and installed in the computer therefrom.

  Hereinafter, the operation of the film forming apparatus 2 according to the present embodiment will be described. The wafer W stored in the FOUP 4 on the mounting table 21 is taken out of the FOUP 4 by the first transfer device 23 and positioned in the alignment chamber 24 while being transferred in the first transfer chamber 22. It is delivered to the left or right load lock chamber 25 and waits. When the inside of the load lock chamber 25 is in a vacuum atmosphere, the wafer W is taken out of the load lock chamber 25 by the holding arms 1a and 1b of the second transfer device 27 and transferred into the second transfer chamber 26. These vacuum vessels 28a to 28d are subjected to a predetermined heat treatment, for example, a film forming process by CVD or ALD in this example. When different continuous processing is performed in the vacuum containers 28a to 28d, the wafer W is transferred between the vacuum containers 28a to 28d necessary for the continuous processing while reciprocating between the second transfer chamber 26 and the wafer W. The Then, the wafer W that has undergone the necessary processing is transported along a path opposite to that at the time of loading (except for the alignment chamber 24), and stored in the FOUP 4 again.

  The wafer W transferred through the film forming apparatus 2 through such a normal path is held on the wafer holding member 10 of the holding arms 1a and 1b of the second transfer apparatus 27 in the second transfer chamber 26. As shown in FIG. 5, the vertical cross section is supported by holding surfaces 13 and 14 having an arcuate concave curved surface. At this time, a reaction force corresponding to a force applied from the wafer W toward the holding surfaces 13 and 14 is applied to the wafer W from the holding surfaces 13 and 14, and a horizontal component of the reaction force is applied toward the center side of the wafer W. ing. For this reason, for example, the wafer W can be pressed against the inertial force that acts when the holding arms 1a and 1b are horizontally moved at a high speed, and the occurrence of positional deviation and dropping of the wafer W can be suppressed.

  Further, as shown in FIG. 6, the wafer holding member 10 according to this example supports the wafer W at a ridge line where the bottom surface of the wafer W and the inclined surface of the bevel portion intersect, and this ridge line (hereinafter referred to as a first ridge line). For example, the ridge line is an obtuse angle compared to the ridge line (also referred to as the second ridge line) where the side peripheral surface of the wafer W and the inclined surface on the bottom surface side of the bevel intersect. For this reason, there is an advantage that the wafer W in contact with the ceramic wafer holding member 10 is less likely to be cut and particles are less likely to be generated than in the case of holding the first edge having a relatively acute angle.

  Further, as described above, the base end side holding surface 13 and the tip end side holding surface 14 are configured as a common inner surface, and the intersection line between the sphere and the bottom surface of the flat wafer W is circular. Therefore, for example, as a result of variations in the size of the wafer W and the size of the bevel within a tolerance range, the size of the first ridge line (the shape of the first ridge line is also a circle when viewed from the bottom side) is obtained. Can change the position of the wafer W at the position corresponding to each first ridge line, as shown by, for example, the solid line and the alternate long and short dash line in FIG. The wafer W can be held in a state where it is difficult to do.

  Furthermore, since the holding surfaces 13 and 14 of the wafer holding member 10 are concave curved surfaces, the inclination of the surface circumscribing the concave curved surfaces with respect to the horizontal direction increases toward the outside. For this reason, as indicated by a solid line in FIG. 8, for example, the wafer W is placed in an inclined state, or the inertial force acting on the wafer W being transferred is large and supported by the concave curved surface. Even in the case where the wafer W is shifted and tilted, the horizontal reaction force acting from the holding surfaces 13 and 14 in the shifted direction toward the wafer W is increased, so that the wafer W is easily pushed back toward the center.

  Further, since the holding surfaces 13 and 14 of the wafer holding member 10 are concave curved surfaces, even when the wafer W is inclined as shown by the solid line in FIG. 8, for example, the holding surfaces 13a and 14a are simply As shown in FIG. 9A, the concave curved surface is recessed further toward the back than in the case of FIG. For this reason, the second ridge line of the wafer W and the holding surfaces 13 and 14 do not easily come into contact with each other, and the contact surface between the wafer W and the holding surfaces 13 and 14 does not need to be large.

  FIG. 10 schematically shows a state in which the wafer W is held by the wafer holding member 10 in a state where the warp in which the central portion of the wafer W protrudes upward is generated. When such a warp occurs, the angle formed by the inclined surface of the bevel portion of the wafer W with respect to the horizontal direction gradually decreases as the warp increases. For this reason, the inclined surfaces gradually approach the holding surfaces 13 and 14 of the wafer holding member 10, but the holding surfaces 13 and 14 are merely inclined surfaces as in the case where the wafer W is inclined and placed. Compared to the above, since it is recessed toward the back side, the inclined surface of the wafer W and the holding surfaces 13 and 14 are less likely to contact each other.

  Further, even if the warpage of the wafer W is further increased and the inclined surface of the bevel portion comes into contact with the holding surfaces 13 and 14, the contact area of the inclined surface of the bevel portion is first, as shown in FIG. Only the second ridge line is present, and the risk of particle generation is small as compared to the case where the entire inclined surface contacts.

Next, FIG. 12 schematically shows a state in which the wafer W is held by the wafer holding member 10 in a state where the warp in which the central portion of the wafer W protrudes downward occurs. In the case of such warpage, the bottom surface of the wafer W approaches the holding surfaces 13 and 14, but the holding surfaces 13 and 14 are recessed downward, for example, flat. Compared to the case where the wafer W is supported from the bottom side on a flat horizontal surface, the bottom surface of the wafer W is less likely to contact the holding surfaces 13 and 14 as shown in FIG.
As described above with reference to FIGS. 10 to 13, the wafer holding member 10 according to the present embodiment has the wafer W and the wafer holding member 10 even when the wafer W is warped in any direction. It can be said that the holding surfaces 13 and 14 are relatively difficult to contact.

  The wafer holding member 10 according to the present embodiment has the following effects. The shape of the holding surfaces 13 and 14 that hold the wafer W provided on the wafer holding member 10 constitutes a part of the inner surface of a sphere, for example, and the vertical cross section is formed as an arcuate concave curved surface. Has been. For this reason, the holding surfaces 13 and 14 support the lower peripheral edge of the wafer W, for example, the ridge line where the bottom surface of the wafer W and the inclined surface of the bevel portion intersect, thereby holding the holding surface 13 and 14 on the wafer W. A horizontal force from the wafer W toward the center of the wafer W acts, and the occurrence of positional deviation of the wafer W can be suppressed against the inertial force acting during acceleration and deceleration during the wafer W transfer. As a result, the wafer W can be transferred at high speed even in the second transfer chamber 26 which is in a vacuum atmosphere and it is difficult to use a vacuum chuck or the like, which contributes to the improvement of the throughput of the film forming apparatus 2. it can.

  Further, even when the wafer W shape varies within the tolerance range, or when the wafer W is warped, the holding surfaces 13 and 14 are concavely curved, so that the wafer W and the wafer holding member are The area of the contact portion with 10 can be kept small, and the generation of particles can be suppressed.

  Here, the concave curved surfaces constituting the holding surfaces 13 and 14 are not limited to being formed so as to constitute a part of the inner surface of the sphere exemplified in the above embodiment. For example, it may be a vertically long elliptical sphere or a part of a horizontally long elliptical sphere, a proximal end holding surface 13 on the proximal end member 11 side, and a distal end holding surface 14 on the distal end side of the support member 12. Concave surfaces with different curvatures may be used. As described above, the “arc” of the “concave curved surface having a circular cross section in the vertical direction” in the present invention is not limited to an arc obtained by cutting a part of a perfect circle, but arcs having various bow shapes such as an ellipse. Contains. Even in the case of such a concave curved surface, for the same reason as in the case of the inner surface of the sphere described with reference to FIGS. Therefore, the wafer holding member 10 in which particles are hardly generated can be configured.

  In the wafer holding member 10 shown in FIG. 3A, the base end side holding surface 13 formed on the base end member 11 side of the base end portion extends over a region between the two support members 12. Although it is configured as an extended continuous surface, the configuration of the holding surface 13 is not limited to this example. For example, a small base end side having the same size as that of the front end side holding surface 14 at a position facing the two front end side holding surfaces 14 on the support member 12 side across the central region of the wafer W. For example, the holding surface 13 may be provided to support the wafer W at four points, for example, or a V-shaped cut may be made as shown in FIG. In contrast to this example, the base end side holding surface 13 may be provided at a position where the wafer W is supported to support the wafer W at three points. By making the proximal end holding surface 13 small, the contact area with the wafer W can be reduced, and generation of particles can be further suppressed. In this case, for example, taking a four-point support as an example, first, the wafer holding member 10 having the base-side holding surface 13 having the continuous surface shown in FIG. 3A by cutting a ceramic sintered body. Then, the unnecessary proximal end holding surface 13 is further cut to leave a small proximal end holding surface 13.

  Further, for example, the fork-shaped wafer holding member 10 is not limited to the case where the support member 12 branched into two is provided, and may be branched into three or more. Further, a plurality of holding surfaces provided along the circumferential direction of the mounting area of the wafer W are provided apart from the base end member 11 and the support member 12 like the wafer holding member 10 shown in FIG. It also includes an annular holding surface formed when such holding surfaces are increased in the circumferential direction of the wafer W as much as possible.

(Experiment)
A holding arm 1 (any one of the holding arms 1a and 1b described above) provided with the wafer holding member 10 according to the embodiment and a conventional type in which the wafer W is placed on a small wafer support portion. The following transfer operation was executed in the atmospheric atmosphere by the holding arm 1 provided with the wafer holding member, and an experiment was performed to obtain the shortest transfer time within a range where the positional deviation of the wafer W is allowed.
Transfer operation: (1) Open the gate valve G2 of the load lock chamber 25 → (2) Advance the holding arm 1 and enter the load lock chamber 25 → (3) Lower the lifter of the stage 251 and move the wafer to the wafer holding member 10 W is transferred → (4) The holding arm 1 is moved backward to exit from the load lock chamber 25 → (5) The holding arm 1 is swung to the vacuum container 28 (any one of the previously described vacuum containers 28a to 28d). (6) Advance the holding arm 1 to enter the vacuum chamber 1 → (7) Raise the lifter and transfer the wafer W to the stage 281 → (8) Retract the holding arm 1 and vacuum Retreat from the container 1 → (9) Close the gate valve G3 of the vacuum container 28.

A. Experimental conditions
Example The wafer W was placed on the holding arm 1 having the wafer holding member 10 shown in FIGS. 3 and 4, and the time required for the above-described transfer operation was measured in the film forming apparatus 2 shown in FIG. . Then, the wafer W was transported a plurality of times while increasing the operating speed of the holding arm 1, and the shortest required time within the range where the positional deviation of the wafer W was within ± 0.05 mm was examined.
(Comparative Example) The wafer W was held by the holding arm 1 provided with the wafer holding member 100 shown in FIG. 14, and an experiment similar to (Example) was performed. In FIG. 14, reference numeral 101 denotes a wafer support unit that supports the wafer W from the bottom surface side.

既述の搬送動作のうち、（１）、（９）のゲートバルブＧ２、Ｇ３の開閉時間、（３）、（７）のリフター昇降時間（ウエハＷの受け渡し時間）は（実施例）及び（比較例）にて共通の動作であり、当該搬送動作全体に要する時間（合計時間）は保持アーム１の動作時間の違いによって差が現れる。 B. Experimental result
The results of (Example) and (Comparative Example) are shown in the following (Table 1). In the table, the control and communication times are times required for judgment and communication in the control unit 3 between the operations (1) to (9).
(Table 1)

Among the transfer operations described above, the opening / closing time of the gate valves G2 and G3 in (1) and (9), and the lifter lifting / lowering time (wafer W transfer time) in (3) and (7) are (Example) and ( This is a common operation in the comparative example), and the time required for the entire transfer operation (total time) differs depending on the operation time of the holding arm 1.

  According to the result of (Example), the time required for the entire transfer operation was 13.88 seconds, and the total time required for the operation of the holding arm 1 was 8.88 seconds. On the other hand, in the (comparative example), the time required for the entire transfer operation is 16.00 seconds, of which the total time required for the operation of the holding arm 1 is 11.00 seconds. When comparing the time, the (Example) was about 20% shorter than the (Comparative Example). This is because the wafer holding member 10 according to the present embodiment that holds the lower peripheral portion of the wafer W with a concave curved surface is a conventional wafer holding member 100 that only supports the wafer W from the bottom surface side. Compared to this, the wafer W is less likely to be displaced, and the wafer W can be transferred at a higher speed. This can also be said to be the same in a vacuum atmosphere in which no air resistance acts on the wafer W.

G1 to G3 Gate valve W Wafer 100 Wafer holding member 101 Wafer support portion 1, 1a, 1b Holding arm 10 Wafer holding member 11 Base end member 12 Support members 13, 13a
Proximal holding surface 14, 14a
Front holding surface 2 Film forming device 22 First transfer chamber 23 First transfer device 26 Second transfer chamber 27 Second transfer device 3 Control unit

Claims (5)

A holding member that holds the substrate and is movable in the horizontal direction;
In order to hold the peripheral portion on the lower surface side of the substrate, the holding member is provided with a plurality of holding surfaces along the circumferential direction of the mounting region of the substrate, and a holding surface whose vertical section is an arc-shaped concave curved surface A substrate transfer apparatus.   The holding member holds the substrate by supporting, on the holding surface, a ridge line where a bottom surface of the substrate, which is a circular substrate having a bevel portion formed on a peripheral portion, and an inclined surface of the bevel portion intersect. The substrate transfer apparatus according to claim 1, wherein   The holding member is formed in a fork shape extending in a plurality of branches from the proximal end portion to the distal end side, the holding surface is formed at each branch portion, and the horizontally long holding surface is formed at the proximal end portion. The substrate transfer apparatus according to claim 1, wherein:   The substrate transfer apparatus according to claim 1, wherein the holding member is made of ceramic. A processing module for performing a heat treatment on the substrate in a vacuum atmosphere;
A transfer chamber that is hermetically connected to the processing module and carries the substrate in and out of the processing module in a vacuum atmosphere;
A substrate processing apparatus, comprising: the substrate transport apparatus according to claim 1 provided in the transport chamber.

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