WO2010113881A1

WO2010113881A1 - Substrate transfer device and substrate processing device

Info

Publication number: WO2010113881A1
Application number: PCT/JP2010/055579
Authority: WO
Inventors: 雅仁小沢; 義明佐々木
Original assignee: 東京エレクトロン株式会社
Priority date: 2009-03-31
Filing date: 2010-03-29
Publication date: 2010-10-07
Also published as: JP2010239023A

Abstract

Provided is a substrate transfer device equipped with a holding member that is capable of holding and horizontally moving a substrate, and a plurality of holding surfaces 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 mounting areas in order to hold the periphery of the bottom surface of the substrate.

Description

Substrate transport apparatus and substrate processing apparatus

The present invention relates to a substrate transfer apparatus that transfers a substrate during substrate processing, and a substrate processing apparatus including the substrate transfer apparatus. In particular, the present invention relates to a technique for transporting a substrate in a vacuum atmosphere where application of a vacuum chuck or the like is difficult.

In the manufacturing process of a semiconductor device, for example, CVD (Chemical Vapor Deposition) is performed to supply a source gas in a vacuum atmosphere to the surface of a heated semiconductor wafer (hereinafter referred to as a wafer) and form a film on the surface of the wafer. There is a heat treatment. For the purpose of increasing the in-plane uniformity of film thickness, a single-wafer type substrate processing apparatus is used that carries wafers one by one into a vacuum vessel and performs heat treatment.

In a single-wafer type substrate processing apparatus, a plurality of processing modules including vacuum containers 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 of devices called multi-chambers, cluster tools, etc. that have improved throughput.

In the multi-chamber transfer chamber, a wafer transfer device having a holding member is provided. 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. In addition, since it is necessary to quickly transfer the wafer to and from the processing module, it is not practical to provide a mechanical chuck. For this reason, for example, on a fork-shaped ceramic member, for example, a plurality of wafer support portions made of, for example, flat small pieces of disks are provided, and a wafer is placed on these wafer support portions. There is a holding member of a type that conveys a wafer in the state of.

On the other hand, the multi-chamber type substrate processing apparatus is required to further improve the throughput. Along with this, it is also necessary to transport the wafer at a higher speed. In this case, a horizontal inertial force is applied to the wafer when accelerating when the holding member starts moving or when decelerating when the holding member is stopped. However, the inertial force applied to the wafer can be increased by increasing the transfer speed. High nature. However, as described above, with a holding member that simply mounts a wafer on the wafer support, there is only a frictional force that acts between the wafer and the wafer support to resist such inertial force. There is a problem that is likely to occur. In some cases, the wafer may even fall. For this reason, the wafer transfer speed cannot be increased to a desired speed, which may limit throughput. Alternatively, for example, high-speed acceleration control such as acceleration / deceleration must be performed along a predetermined speed curve so that a sudden inertia force is not applied to the wafer, resulting in a complicated apparatus configuration. .

To deal with such problems, for example, Patent Document 1 (Japanese Patent Laid-Open No. 2003-282670: in particular, see 0036 paragraph, 0039 paragraph to 0043 paragraph, FIG. 5 and FIG. 6) is provided with a horizontal plane and a vertical plane orthogonal to each other. For example, two sets of the regulating member and the inclined member provided with the inclined surface are arranged so that the regulating member and the inclined member are opposed to each other across the center of the wafer. And a holding member that positions the wafer by supporting the wafer from the lower surface side by the horizontal surface of the regulating member and the inclined surface of the inclined member while regulating the horizontal displacement of the wafer by the inclined surface of the inclined member. Has been.

In Patent Document 2 (Japanese Patent Laid-Open No. 2005-123642, in particular, see paragraphs 0020, 0053, and FIG. 3), the side curved along the outer surface of the wafer is used for horizontal positioning of the wafer. A holding member that includes a substrate support block having a wall surface and supports the bottom surface of the wafer is described.

Further, in Patent Document 3 (Japanese Patent Laid-Open No. 2000-3951: in particular, see paragraph 0019, FIG. 4), for example, wafer holding members protruding in a mountain shape are provided at four locations, and these mountain-shaped wafer holding members are provided. A holding member is described in which the wafer is held by the inclined surface of the member and the wafer is pressed from the bottom surface side and the outer peripheral direction so that the wafer is hardly displaced.

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 or 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-mentioned CVD, for example, a film is also formed on the peripheral portion and the side peripheral surface of the wafer. When this portion comes into contact with the holding member, the film is scraped and becomes a cause of generation of particles. For this reason, the contact portion between the wafer and the holding member is preferably as small as possible. However, as described in Patent Document 1 and Patent Document 2, in the holding member that supports the wafer from the bottom surface side and suppresses the deviation of the wafer on the surface extending in the vertical direction, the holding member and the wafer are in contact with each other at at least two locations. It is a premise. That is, there are many contact locations, and there is a high possibility that particles will be generated at those locations.

On the other hand, the holding member that supports the wafer with the inclined surface as described in Patent Document 1 or Patent Document 3 has fewer contact points with the wafer than the holding member that holds the bottom surface and the side surface. However, the wafer is provided with a region where an inclined surface called a bevel portion is formed, and the shape of the bevel portion varies from wafer to wafer within a tolerance range. 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 increase, and particles may be easily generated. There is. 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 these, in the holding member described in Patent Document 3, it is difficult to ensure chamfering and positioning processing accuracy because it is difficult to form the wafer holding member protruding in a chevron shape with ceramic or the like. Is usually made of elastomer. However, since elastomer is softer than a wafer, there is a possibility that the wafer holding member side is scraped and particles are generated. In addition, when CVD is performed on a wafer, since the process temperature is high, a holding member made of an elastomer having low heat resistance cannot be used.

Summary of the Invention

The present invention has been made based on such circumstances, and the purpose thereof is to provide a substrate transport device that is less likely to cause a positional deviation of the substrate during transport and can suppress generation of particles, and An object of the present invention is to provide a substrate processing apparatus provided with a substrate transfer apparatus.

The present invention is provided with a plurality of holding members that can move in the horizontal direction while holding the substrate, and a circumferential direction of the substrate mounting area of the holding member in order to hold the peripheral portion on the lower surface side of the substrate. And a holding surface that is a concave curved surface having a circular cross section in the vertical direction.

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. The peripheral edge on the side is supported, and a horizontal force from the concave curved surface toward the center of the substrate acts on the substrate. This force can resist the inertial force that acts when accelerating or decelerating the substrate when it is transported, thereby suppressing the occurrence of substrate displacement. 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, effectively suppressing the generation of particles. Can do.

Preferably, 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 each other. It is supposed to be.

Preferably, 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 in each branch portion, and the proximal end portion The horizontally long holding surface is formed.

Also preferably, the holding member is made of ceramic.

Alternatively, the present invention provides a processing module for performing a heat treatment on a substrate in a vacuum atmosphere, and 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 a substrate transfer apparatus having any one of the above characteristics provided in the transfer chamber.

It is a top view of the film-forming apparatus which concerns on one embodiment of this invention. 1 is a perspective view showing a configuration of a holding arm provided in a second transfer chamber of the 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 holding arm of FIG. FIG. 4 is a perspective view showing a state where a wafer is held by the wafer holding member of FIG. 3. It is explanatory drawing which shows the state which hold | maintained the wafer with the wafer holding member of FIG. It is an enlarged view which shows the contact state of the holding surface of the wafer holding member of FIG. 3, 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 wafer holding member of FIG. FIG. 4 is an enlarged view showing a contact state between the holding surface of the wafer holding member of FIG. 3 and the inclined wafer. FIG. 4 is an enlarged view showing a contact state between the holding surface of the wafer holding member of FIG. 3 and the inclined wafer. FIG. 4 is an explanatory view showing a state where the wafer holding member in FIG. 3 holds the wafer in a state in which a warp in which the central portion protrudes upward occurs. FIG. 4 is an enlarged view showing a contact state between the holding surface of the wafer holding member of FIG. 3 and the wafer warped upward. FIG. 4 is an explanatory view showing a state where the wafer holding member in FIG. 3 holds a wafer in a state where a warp in which a central portion protrudes downward occurs. FIG. 4 is an enlarged view showing a contact state between a holding surface of the wafer holding member of FIG. 3 and a wafer that is warped downward. It is a perspective view which shows the structure of the wafer holding member which concerns on a comparative example.

Hereinafter, a substrate transfer 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 wafers W taken out from 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, and a second transfer for transferring the wafer W in a vacuum atmosphere A chamber 26 and, for example, four vacuum vessels 28a to 28d for performing a film forming process on the loaded wafer W are provided.

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 28a to 28d with respect to the loading direction of the wafer W. Adjacent devices are hermetically connected via 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. During the lifting / lowering operation, the lid provided on the side surface of the FOUP 4 opens and closes, so that the wafer W can be taken out and stored between the first transfer chamber 22 and the FOUP 4.

In the first transfer chamber 22, there is a transfer device that is rotatable, telescopic, liftable, and movable in the left-right direction along the running track 232 for taking out and transferring the wafers W from the FOUP 4 one by one. A first transport device 23 is installed. The first transport device 23 includes holding

arms

231a and 231b made of, for example, two SCARA-type articulated arms. These holding

arms

231 a and 231 b can transfer the wafer W between each FOUP 4, an alignment chamber 24 described later, and a load lock chamber 25. As shown in FIG. 1, each holding

arm

231a, 231b includes a fork-shaped wafer holding member divided into two forks. A vacuum chuck (not shown) is provided on the contact surface of the wafer holding member with the wafer W, and the wafer W is resisted against the inertial force that acts during acceleration and deceleration even when the wafer W is transferred at high speed. It can be fixed and held.

When viewed from the front side of the first transfer chamber 22, for example, an alignment chamber 24 for aligning the wafer W is provided on the side wall surface of the left hand. In the alignment chamber 24, for example, an orienter 241 including an optical sensor for detecting a notch or an orientation flat provided on the wafer W and a turntable for performing alignment of the wafer W is provided. Thus, before the wafer W taken out from each 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.

In addition, a fan filter unit (not shown) including a fan that sends air into the room and a filter that cleans the air is provided on the ceiling of the first transfer chamber 22. In addition, an exhaust unit (not shown) is provided on the floor facing the floor. Thereby, a descending airflow 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 G1, respectively. Each load lock chamber 25 includes a stage 251 for placing a wafer W, and is connected to a vacuum pump and a leak valve (not shown) for switching the load lock chamber 25 between an air atmosphere and a vacuum atmosphere.

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, each load lock chamber 25 is configured as a casing having, for example, a hexagonal shape in plan view. Then, the side wall surface that forms the two sides of the hexagonal front side is connected to the load lock chamber 25 described above, while the remaining side wall surface that forms the four sides is subjected to a film forming process that is a heat treatment for the wafer W. The vacuum containers 28a to 28d to be executed are connected. In the second transfer chamber 26, the substrate 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 transport device 27 that is a transport device is installed. 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 containers 28a to 28d includes, for example, a stage 281 on which a wafer W is mounted and a heat source for heating the wafer W, and a gas supply mechanism (not shown) to which process gas is supplied. It is connected to a vacuum pump (not shown). Thus, the heat treatment is performed in a vacuum atmosphere, for example, a processing module that performs film forming processing by thermal CVD using a film forming gas, ALD (Atomic Layer Deposition), or the like. In each of the vacuum containers 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. Further, the contents of the process processing executed in these vacuum vessels 28a to 28d may be the same or different.

In the film forming apparatus 2 having the configuration described above, according to the second transfer device 27 provided in the second transfer chamber 26, the wafer W can be formed at high speed in a vacuum atmosphere where it is difficult to apply a vacuum chuck. Even if the wafer is transferred, the wafer W is less likely to be displaced or dropped. Further, even when there is a variation in the shape of the wafer W or when the wafer W is warped, the area of the contact portion with the wafer W can be kept small, and the generation of particles can be suppressed. The detailed configuration will be described below.

The second transport device 27 includes, for example, two holding

arms

1a and 1b. For example, as shown in FIG. 2, each holding

arm

1a, 1b includes a revolving arm unit 18, a middle arm unit 17, and a support arm unit 16 in this order from the base end side through a rotation shaft (not shown). It is configured as a connected SCARA-type articulated arm. The base end side of the turning arm portion 18 is connected to the main body of the second transport device 27 via the turning shaft 19 so as to be turnable. On the other hand, a wafer holding member 10, which is a holding member for holding the wafer W, is fixed to the distal end portion of the support arm portion 16.

Further, a rotating shaft for extending and retracting each of the arm portions 16 to 18 is provided in the turning shaft 19. By rotating the rotating shaft by a motor, pulleys provided at joint portions of the arm portions 16 to 18 are rotated via belts. Thereby, the wafer holding member 10 can be linearly moved in the horizontal direction. These rotary shafts, motors, pulleys, and the like constitute an advancing / retreating mechanism that moves the wafer holding member 10 back and forth, although not shown. 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.

3 (a) and 3 (b) are a plan view and a side view of the wafer holding member 10 according to the present embodiment provided at the distal ends 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 plurality of, for example, two, for example, two support members 12 that are flat and elongated members extending in a branching manner from the end portion toward the front end portion are integrally formed. That is, it is configured as a member having a fork-shaped appearance divided into two forks. The wafer holding member 10 is formed by, for example, cutting a ceramic sintered body such as alumina.

As shown in FIG. 3B, each of the two support members 12 has a base end portion connected to the base end member 11 and a thickness “h1” of the front end portion of about 4 mm, for example. The thickness “h2” of the region sandwiched between the tip portions is, for example, about 2 mm, and the boundary between the regions having different thicknesses is continuously connected by a concave curved surface. These concave curved surfaces constitute the holding surfaces 13 and 14 of the wafer W.

Hereinafter, the holding surface on the proximal end side is referred to as a proximal end holding surface 13, and the holding surface on the distal end side is referred to as a distal end holding surface 14. As shown in FIG. 3A, the base end side holding surface 13 is formed on the base end member 11 as a horizontally long continuous surface extending over a region between the two support members 12. When viewed from the upper surface side, this continuous surface has an elongated arc shape obtained by cutting out a part of an annular region S that can support, for example, a wafer W having a diameter of 300 mm from the bottom surface side. On the other hand, each of the distal-side holding surfaces 14 provided at the distal end portion of the support member 12 that is a bifurcated portion is also an annular region common to the arc-shaped region on the proximal-side holding surface 13 side. It is formed in a short arc shape with a part of S cut off. A thick portion formed along the proximal end holding surface 13 in the outer peripheral region of the proximal end holding surface 13 is a rib 15 for maintaining the strength of the wafer holding member 10.

With 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. In this state, the wafer W can be transferred in the second transfer chamber 26 by operating the

scalar holding arms

1a and 1b. 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 surface constituting the base end side holding surface 13 and the tip end side holding surface 14 has the characteristics described below, thereby suppressing positional deviation during the transfer of the wafer W and having a contact area with the wafer W. It is getting smaller.

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 have a distance R from a predetermined center O of about 390 mm, for example. It is configured as part of the inner surface of the sphere. The vertical cross section of the concave curved surface is arcuate. In addition, 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, the shape of these concave curved surfaces will be described in detail. As shown in FIG. 5, the concave curved surface has a height H of about 2 mm, an opening diameter L1 of the holding surfaces 13 and 14 of about 305 mm, and a holding surface. The diameter L2 on the bottom side of 13 and 14 is 295 mm, and is formed so as to correspond to the above-described annular region S shown in FIG. As shown in FIG. 8, the wafer W can be supported by the holding surfaces 13 and 14 even when the wafer W is tilted during placement or transfer.

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 part 3 consists of a computer provided with CPU and a memory | storage part which are not illustrated, for example. In the storage unit, the operation of the film forming apparatus 2, that is, the wafer W is taken out from the FOUP 4 placed on the placement table 21, and loaded into each of the vacuum containers 28a to 28d and subjected to heat treatment such as CVD or ALD, Thereafter, a program in which a group of steps (commands) for control related to the operation until the wafer W is stored in the FOUP 4 is recorded again. In general, 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 then installed in a computer.

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. . Thereafter, 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 from 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. In any one of the vacuum vessels 28a to 28d, a predetermined heat treatment, for example, a film forming process by CVD or ALD is performed in this example. Here, when different continuous processing is performed in the vacuum containers 28a to 28d, the wafer W moves back and forth between the second transfer chamber 26 and between the vacuum containers 28a to 28d necessary for the continuous processing. Be transported. Then, the wafer W that has undergone the necessary processing is transferred along the path opposite to that at the time of loading (except for the alignment chamber 24), and is 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

1 a and 1 b of the second transfer apparatus 27 in the second transfer chamber 26. . Specifically, 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 the force applied from the wafer W toward the holding surfaces 13 and 14 acts on the wafer W from the holding surfaces 13 and 14. The horizontal component of the reaction force works toward the center of the wafer W. For this reason, the horizontal component of the reaction force presses the wafer W against the inertial force acting when the holding

arms

1a and 1b are horizontally moved at high speed, for example, and suppresses the occurrence of positional deviation or dropping of the wafer W. it can.

Further, as shown in FIG. 6, the wafer holding member 10 according to the present example supports the wafer W at a ridge line where the bottom surface of the wafer W intersects with the inclined surface of the bevel portion. 1) is an obtuse angle compared to, for example, a ridge line (also referred to as a second ridge line) where the side peripheral surface of the wafer W and the inclined surface on the bottom surface side of the bevel portion 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 as compared with the case of holding the second edge having a relatively acute angle.

Further, as described above, the proximal end side holding surface 13 and the distal end side holding surface 14 are configured as a common spherical inner surface. Here, the line of intersection between the spherical surface 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. Even when is changed, the wafer W can be supported at a position corresponding to each first ridge line, for example, as indicated by a solid line and a one-dot chain line in FIG. As a result, it is possible to always hold the wafer W in a state in which the positional deviation and the particles are hardly generated.

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 surface with respect to the horizontal direction becomes larger toward the outside. For this reason, as shown 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 a concave curved surface. Even when 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. Become.

Furthermore, since the holding surfaces 13 and 14 of the wafer holding member 10 are concave curved surfaces, as shown by the solid line in FIG. 8, even when the wafer W is inclined, for example, the holding

surfaces

13a and 14a are Compared with the case of FIG. 9B which consists of a simple inclined surface, as shown to FIG. 9A, the concave curved surface is dented toward the back | inner side. For this reason, the second ridge line of the wafer W and the holding surfaces 13 and 14 are hardly in contact with each other, and the contact surface between the wafer W and the holding surfaces 13 and 14 does not have to be large.

FIG. 10 schematically shows a state where the wafer holding member 10 holds the wafer W in a state where the warp in which the central portion of the wafer W protrudes upward occurs. 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 as in the case where the wafer W is placed inclined. Since the surface is recessed further toward the back than the surface, 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, as shown in an enlarged view in FIG. Only the first and second ridge lines are present, and the risk of particle generation is small as compared with the case where the entire inclined surface contacts.

Next, FIG. 12 schematically shows a state in which the wafer W in a state where the warp in which the central portion of the wafer W protrudes downward is held by the wafer holding member 10 is shown. In the case of such warping, the bottom surface of the wafer W gradually approaches the holding surfaces 13 and 14, but since these holding

surfaces

13 and 14 are recessed downward, for example, they are flat. Compared with the case where the wafer W is supported from the bottom side on a flat horizontal surface, the bottom surface of the wafer W and the holding surfaces 13 and 14 are less likely to contact each other as shown in FIG. In this respect, particles are not easily generated.
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 regardless of whether 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 thereof becomes an arc-shaped concave curved surface. Therefore, the supporting

surfaces

13 and 14 support the peripheral edge of the lower side of the wafer W, for example, the ridge line where the bottom surface of the wafer W and the inclined surface of the bevel intersect, A horizontal force from the holding surfaces 13 and 14 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 that acts during acceleration and deceleration when the wafer W is transferred. . 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. be able to.

Furthermore, 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 are held. The area of the contact portion with the member 10 is kept small. Thereby, generation | occurrence | production of a particle can be suppressed.

Here, the concave curved surface constituting the holding surfaces 13 and 14 is not limited to a form constituting a part of the inner surface of the sphere as exemplified in the above-described embodiment. For example, it may be a part of a vertically long elliptical sphere in the vertical direction or a horizontally long elliptical sphere in the horizontal direction. Further, the proximal end holding surface 13 on the proximal end member 11 side and the distal end holding surface 14 on the distal end side of the support member 12 may be concave curved surfaces having different curvatures. As described above, the “arc” in the “curved concave surface having a circular cross section in the vertical direction” in the present invention is not limited to an arc obtained by cutting out a part of a perfect circle, but various arcuate shapes such as a part of an ellipse. The arc is included. In any of these concave curved surfaces, as in the case of the inner surface of the sphere described with reference to FIGS. 5 to 13, the effect of suppressing the positional deviation of the wafer W during transfer and the contact surface with the wafer W are small. Therefore, an effect that particles are hardly generated can be obtained.

Further, 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. However, the configuration of the holding surface 13 is not limited to this example. For example, a small base end having a size similar to 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 with the central region of the wafer W interposed therebetween. For example, the side holding surface 13 may be provided to support the wafer W at, for example, four points. Alternatively, as shown in FIG. 3A, the base end side holding surface 13 is provided at a position where the base end side holding surface 13 is cut out in a V shape and the wafer W is attached at three points. You may support. By making the base end side holding surface 13 small, the contact area with the wafer W becomes small, and generation of particles can be further suppressed. For example, in the case of a four-point support, for example, a wafer holding having a proximal-side holding surface 13 having a continuous surface as shown in FIG. 3A is first performed by cutting a ceramic sintered body. The member 10 is manufactured, and then the unnecessary proximal end holding surface 13 is further cut to form 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)
Conventionally, a wafer W is placed on a holding arm 1 (any one of the holding

arms

1a and 1b described above) including the wafer holding member 10 according to the above-described embodiment, and a small piece of wafer support. Each of the holding arms 1 provided with a mold wafer holding member performed the following transfer operation in an air atmosphere. Then, the shortest transfer time within the range in which the positional deviation of the wafer W is allowed was obtained.
Transport operation:
(1) Open the gate valve G2 of the load lock chamber 25 →
(2) The holding arm 1 is moved forward to enter the load lock chamber 25 →
(3) Lower the lifter of the stage 251 and deliver the wafer W to the wafer holding member 10 →
(4) The holding arm 1 is moved backward to exit from the load lock chamber 25 →
(5) The holding arm 1 is turned so as to face the vacuum vessel 28 (any one of the previously described vacuum vessels 28a to 28d).
(6) The holding arm 1 is moved forward to enter the vacuum vessel 1 →
(7) Raise the lifter and deliver the wafer W to the stage 281 →
(8) Retract the holding arm 1 and retreat from the vacuum vessel 1 →
(9) The gate valve G3 of the vacuum vessel 28 is closed.

A. Experimental conditions
Example The wafer W is 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 is measured in the film forming apparatus 2 shown in FIG. did. Then, while increasing the operating speed of the holding arm 1, the wafer W was transported a plurality of times, and the shortest required time within a range where the positional deviation of the wafer W was within ± 0.05 mm was examined.
(Comparative Example) The wafer W was placed on the holding arm 1 having the wafer holding member 100 shown in FIG. 14, and an experiment was performed in the same procedure as in the above (Example). In FIG. 14, reference numeral 101 denotes a wafer support unit that supports the wafer W from the bottom surface side.

B. Experimental result
The results of (Example) and (Comparative Example) are shown in the following (Table 1). In Table 1, the control and communication time is the time required for judgment and communication in the control unit 3 between the operations (1) to (9).

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 (transfer time of the wafer W) in (3) and (7) are as follows. ) And (comparative example). On the other hand, the time required for the entire transport operation (total time) varies 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 (Comparative Example), the time required for the entire transport operation was 16.00 seconds, and the total time required for the operation of the holding arm 1 was 11.00 seconds. Comparing the operation time of both holding arms 1, 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. In comparison, 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 air resistance does not act on the wafer W.

Claims

A holding member that holds the substrate and is movable in the horizontal direction;
In order to hold the peripheral edge of the lower surface side of the substrate, a plurality of holding surfaces provided along the circumferential direction of the mounting region of the substrate in the holding member, and a holding surface whose vertical cross section is an arcuate concave curved surface;
A substrate transfer device comprising:
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 the peripheral portion, and an inclined surface of the bevel portion intersect each other. The substrate transfer apparatus according to claim 1, wherein
The holding member is formed in a fork shape extending a plurality of branches from the proximal end portion to the distal end side,
The holding surface is formed on each branch part,
3. The substrate transfer apparatus according to claim 1, wherein the horizontally long holding surface is formed at the base end portion.
The substrate transport apparatus according to claim 1, wherein the holding member is made of ceramic.
A processing module for performing 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;
The substrate transfer apparatus according to any one of claims 1 to 4, provided in the transfer chamber;
A substrate processing apparatus comprising: