JPH08153771A - Device and method for supplying and discharging wafer - Google Patents

Abstract

PURPOSE: To supply a wafer to a holding device by turning over the wafer while one surface is protected by providing a positioning member which comes into contact with the outer peripheral side-face of the wafer sent to the holding device from the lateral direction, centers the wafer to a prescribed position, and receives the wafer. CONSTITUTION: A suction arm 14 attracts and holds a wafer 12 by suction through a suction port 14b. An inverting mechanism turns the arm 14 by a prescribed angle. When the vacuum is canceled, the wafer 12 moves a very short distance by sliding on the attracting surface of the arm 14 and an arcuate receiving section 14c comes into contact with the outer peripheral side-face of the wafer 12 and receives the wafer 12. Then the arm 14 is further rotated and turns over the wafer 12 so that its polishing surface can come to the bottom side. After turning over, the wafer 12 is supplied to a position C by moving the arm 14 by means of a feeding mechanism and centered by means of the paired positioning members 22b of a centering mechanism 22. Then, after the mechanism 22 is lowered and the arm 14 is returned to a position B, a holding device 10 attracts the wafer 12 by suction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wafer supplying apparatus and a wafer discharging apparatus.

[0002]

2. Description of the Related Art An apparatus for supplying a wafer, which is a thin plate-like work, to a holding device which comes into contact with an upper surface of the wafer and holds the wafer by suction so that the wafer stored in a cassette is sent to a predetermined position. A supply device including a conveyor device is used. Further, as an apparatus for ejecting the wafer sucked and held by the holding apparatus, an ejecting apparatus having a shooter for receiving the wafer whose holding by the holding apparatus is released and guiding it to the cassette is used.

As an example of a processing apparatus using such a supply / discharge apparatus, there is a polishing apparatus for polishing the outer periphery of a silicon wafer which is a raw material for semiconductor chips. Conventionally, a conveyor device as shown in FIG. 19 is used as a wafer supply device of this polishing apparatus. 120 is a belt,
It is formed by a rubber band having a circular cross section. 122
a is an outer roller and 122b is an inner roller.
4 are fixed in pairs on both sides. Outer roller 12
Grooves are formed on the outer circumferences of the inner roller 122b and the inner roller 122b so that the inner ring side of the belt 120 fits. Between the two front and rear outer rollers 122a, the front and rear two inner rollers 122b
Belts 120 are alternately stretched between them. By thus stretching the belt 120, the plurality of shafts 1
24 can rotate in synchronization. That is, one shaft 124
By rotating the motor 128 by a motor 128, a plurality of rotating shafts 124 linked by the belt 120 can rotate synchronously, and the wafer 12 placed on the belt 120 can be fed as a conveyor device. By the way, the reason why a plurality of belts 120 are used is that the length of each belt 120 is shortened so that the slack of the belt 120 is reduced,
This is for suppressing the influence of twisting to be small and for reliably transporting the wafer 12.

In this conveyor device, the belt 120 contacts the lower surface of the wafer 12 and conveys the wafer 12 to a predetermined position. At this time, the wafer 1
Reference numeral 2 denotes a surface (polishing surface) whose upper surface is mirror-finished, and whose lower surface is attached to a holding plate which holds the wafer 12 when the polishing surface is mirror-finished ( It is stored in a cassette so that it becomes the (adhesion surface) and is carried in. The conveyor device is arranged so as to be able to come into contact with the wafer 12 housed in a cassette (not shown) from below, and the cassette is vertically movable by an elevating device. Therefore, by lowering the cassette by a predetermined pitch, the wafer 12 is received so that it can be carried on the conveyor device. Then, the wafer 12 is carried by the conveyor device to a predetermined position held by the holding device. For example, as shown in FIG. 19, the stopper member 12
6 is moved to the position where it abuts. In this way, the wafer 12 is transferred to a predetermined position and then centered,
A holding device contacts the upper side, which is the polishing surface of the wafer, from the upper side and sucks and holds the wafer 12. As described above, the wafer 12 held by the holding device is sent to the processing station while being held by the holding portion, and the outer peripheral side surface of the wafer 12 is polished by the buff and the polishing liquid in the processing station.

Next, a conventional mechanism for ejecting a wafer in the polishing apparatus will be described. In the polishing apparatus, the holding device is in contact with the upper surface, which is the polishing surface of the wafer, to suck and hold the wafer. The wafer released from the holding device is dropped onto a shooter in which running water flows on the surface so as not to receive an impact, moves along the shooter surface in water, and is stored in a cassette. At this time, the wafer is stored in a cassette having a large number of shelves so that the upper surface thereof is a polishing surface and the lower surface thereof is a bonding surface. The shooter is provided on an inclined surface, and is formed so as to guide the wafer to a cassette in which the shelves are inclined so as to be continuous with the inclined surface of the shooter. In this way, the wafer is ejected and stored in the cassette so that the polishing surface of the wafer faces upward, as in the case where the wafer is loaded by the supply device.

[0006]

By the way, in recent years, the processing of wafers has become finer, and high polishing accuracy and flatness are required for the polishing surface of the wafer to be mirror-finished, and the wafer surface has a small amount. It is not allowed to get hurt. Therefore, there is an increasing need to protect the wafer surface also in the mirror polishing step of the outer peripheral side surface performed as a step before the final mirror polishing step of the polishing surface of the wafer. Further, in order to reduce the polishing amount of the polishing surface to obtain a predetermined mirror surface precision and flatness, it is not allowed that the polishing surface is slightly scratched.

However, when the wafer is accommodated in the cassette such that the polishing surface is on the upper side and the bonding surface is on the lower side, according to the above-mentioned conventional supplying device, the holding device has the polishing surface. Therefore, there is a problem in that the polishing surface is scratched because it comes into contact with the upper side and is adsorbed and held. Further, in the case where the wafer is stored in the cassette so that the bonding surface is on the upper side and the polishing surface is on the lower side, according to the above-mentioned conventional supply device,
The holding device is in contact with the upper side, which is the bonding surface, and holds it by suction, but when the wafer is conveyed by the conveyor device, slippage occurs between the lower surface, which is the polishing surface, and the belt, and the polishing surface Has the problem of being hurt.
Further, when one surface is used as a reference surface or the like, there is also a problem that the surface must be appropriately protected so as not to be damaged.

Therefore, the present invention has been made to solve the above problems, and an object of the present invention is to provide a wafer accommodated in a cassette so that one surface thereof faces upward.
It is an object of the present invention to provide a wafer supply device capable of reversing and supplying the wafer to a holding device while protecting one surface of the wafer. Another object of the present invention is to provide an ejection device that can store a wafer held by a holding device so that one surface of the wafer faces downward in a cassette while protecting one surface of the wafer.

[0009]

The present invention has the following constitution in order to achieve the above object. That is, the present invention is a wafer supply device that supplies the wafer to a holding device that adsorbs and holds the wafer by contacting the one surface of the wafer on the upper side, and the one surface is a lower side. And a suction member that comes into contact with the one surface of the wafer housed in the cassette and picks up the wafer by suction, and a reversing mechanism that rotates the suction member and reverses the wafer so that one surface is on the upper side. And a feeding mechanism that moves the suction member and the reversing mechanism to feed the wafer to a holding position where the wafer is held by the holding device, and a lateral side surface of the outer peripheral surface of the wafer sent to the holding position by the feeding mechanism. And a centering mechanism having a positioning member that abuts from the center to center and receive the wafer at a predetermined position.

When the suction member that has sucked and picked up a wafer rotates by a predetermined angle and the suction surface of the suction member that sucks the wafer becomes an inclined surface, the suction by the suction member is released to cause the suction. A wafer that moves minutely along the surface is received by abutting on the outer peripheral side surface of the wafer, and the suction member is provided with a receiving portion for temporarily centering the wafer on the suction surface of the suction member. It is possible to supply accurately to the holding position by the holding device. Also,
The wafer has a disk shape, and the receiving portion provided in the suction member is formed in an arc shape so as to correspond to the outer peripheral shape of the wafer, so that a notch portion is formed in the disk wafer. Even in such a case, the temporary centering can be preferably performed.

Further, the present invention is a wafer supply method for supplying the wafer to a holding device for adsorbing and holding the wafer, with one surface of the wafer facing upward and contacting the one surface of the wafer. The suction member is brought into contact with the one surface of the wafer housed in the cassette so that it is on the lower side, the wafer is sucked and taken out, and the suction member is released to be received by the receiving member. The wafer is tentatively centered by laterally contacting the outer peripheral side surface of the wafer, the wafer is again sucked by the suction member, and the suction member is adjusted so that one surface of the wafer is on the upper side in the suctioned state. The wafer is rotated to invert the wafer, the wafer is sent to the holding position where the wafer is held by the holding device, and the outer peripheral side surface of the wafer sent to the holding position is laterally separated. Positioning member Taringu mechanism abuts also on the wafer supply method characterized by centering the wafer in place.

Further, the present invention provides a wafer discharging device for discharging a wafer held by a holding device that holds one wafer by adsorbing and holding the one surface of one side of the wafer with the one side facing upward. Holding means for receiving and holding the wafer held by, and when the holding of the wafer by the holding means is released, the wafer,
A shooter having an inclined surface that guides it to be slid and housed in an inclined cassette, and the holding means is rotated so that the inclined surface of the shooter and the surface of the wafer are substantially parallel to each other. And a rotating mechanism.

Further, the present invention provides a wafer discharging device for discharging a wafer held by a holding device for holding the wafer by sucking and holding one surface of the wafer as an upper side, the holding device being the holding device. And a clamping device that clamps the wafer by laterally contacting the outer peripheral side surface of the wafer with a plurality of clamping pieces approaching from the lower side of the wafer held by the clamping device, and the clamping of the wafer by the clamping device is released. At this time, the wafer has a shooter having an inclined surface that guides the wafer to be slid and stored in a cassette that is arranged at an inclination; A wafer ejecting device, comprising: a rotating mechanism for rotating the holding device such that a surface and an inclined surface of the shooter are substantially parallel to each other.

Further, since the direction in which the wafer is held by the holding device is substantially perpendicular to the direction in which the wafer is discharged into the cassette, it does not become an obstacle when the wafer is discharged, and the wafer can be smoothly moved. Can be discharged.

Further, the present invention provides a wafer discharging device for discharging a wafer held by a holding device for holding one wafer by adsorbing and holding the one surface with one surface of the wafer facing upwards. When the holding by the suction unit is released and placed on the receiving portion, a suction device that approaches the wafer from the upper side by suction and holds the wafer, and when the holding of the wafer by the suction device is released, the wafer And a shooter having an inclined surface that guides the device to be slid and stored in an inclined cassette, and one surface of the wafer with the one surface facing downward and the inclination of the one surface of the wafer and the shooter. And a rotation mechanism that rotates the suction device so that the surface is substantially parallel to the surface.

Further, a wafer feeding / discharging device comprising the above-mentioned wafer feeding device and the above-mentioned wafer discharging device has a function of protecting the polishing surface which is one surface of the wafer. It can be effectively used for a polishing device for polishing the outer periphery, a polishing device for a wafer, or the like.

Further, according to the present invention, there is provided a shooter in which a wafer is received and held by a holding means, and a rotating mechanism for rotating the holding means guides the wafer to be housed in an inclined cassette. The wafer is discharged so that it is rotated substantially parallel to the inclined surface, the holding by the holding means is released, and the wafer is slid along the inclined surface of the shooter and stored in a cassette. There is also a method.

[0018]

According to the wafer supply apparatus of the present invention according to claim 1, first, the suction member has one surface (polishing surface).
Is in contact with the sticking surface which is the other surface of the wafer housed in the cassette, and the wafer is sucked and taken out. The suction member is rotated by the reversing mechanism, and the wafer is reversed so that the sticking surface faces upward. The wafer thus inverted is sent to the holding position where it is held by the holding device by the feeding mechanism. Then, the positioning member of the centering mechanism can laterally contact the outer peripheral side surface of the wafer to center the wafer at a predetermined position. Therefore, the wafer can be supplied to the holding position where the wafer is sucked and held by the holding device and the wafer can be centered without coming into contact with the polishing surface of the wafer. Therefore, the wafer stored in the cassette with the polishing surface facing upward can be preferably supplied to the holding device while protecting the polishing surface.

According to the second aspect of the wafer supply apparatus of the present invention, in the above-mentioned supply apparatus, when the suction member is provided with the receiving portion, the suction member that sucks the wafer and takes it out has a predetermined angle. When the suction surface of the suction member for sucking the wafer becomes a slope, the suction of the wafer by the suction member is released. Then, the receiving portion provided on the suction member receives the wafer that moves slightly along the suction surface of the suction member by abutting the outer peripheral side surface thereof. As a result, the wafer can be temporarily centered on the suction surface of the suction member. The wafer may be temporarily centered on a receiving member provided separately from the suction member. As described above, by temporarily centering the wafer before supplying the wafer to the holding position, the wafer can be more reliably supplied to the centering mechanism.

Further, according to the wafer discharging apparatus of the present invention, the holding means for receiving and holding the wafer can be rotated by the rotating mechanism so that the inclined surface of the shooter and the surface of the wafer are substantially parallel to each other. When the wafer rotated in this manner is released from the holding means, the entire surface of the wafer is suitably dropped so that the entire surface of the wafer contacts the inclined surface of the shooter at substantially the same time, and the wafer is suitably stored in the cassette via the shooter. It

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described in detail below with reference to the accompanying drawings. FIG. 1 is a plan view showing an embodiment of a wafer supply apparatus (hereinafter referred to as a loader) according to the present invention. This loader is used in a polishing apparatus for polishing an outer peripheral surface of a silicon wafer. Also, FIGS.
[Fig. 7] is a schematic view for explaining the operation of the present embodiment, and Figs.
FIG. 3 is an explanatory view showing details of each part of this loader.

A holding device 10 is in contact with the upper surface of the wafer 12 and sucks and holds the wafer 12. The structure of the holding device 10 will be described later with reference to FIG. Reference numeral 14 denotes a suction arm, which is an example of a suction member, and a front end portion 14a thereof is formed in a thin plate shape so as to be able to enter below the wafer 12 stored in the cassette 16. Suction port 14b for adsorbing 12
Is provided. The suction port 14b communicates with a vacuum source (not shown) through a communication hole provided inside the suction arm 14. Further, the suction arm 14 is connected to a moving body 20 which is formed in a substantially U shape and is reciprocally movable along a horizontal guide 18 via a rotary shaft 15, and can move in a horizontal direction. Therefore, the suction arm 14 is such that the attachment surface (the surface attached to the holding plate that holds the wafer when processing the polishing surface of the wafer into a mirror surface), which is one surface of the wafer 12, is on the lower side. Cassette 16
Wafer 1 in contact with the sticking surface of wafer 12 stored in
2 can be adsorbed and taken out. A support member 19 supports the horizontal guide 18 on the base body.
Here, as shown in FIG.
The position stored in 6 is the A position, the position where the wafer 12 is taken out from the cassette 16 is the B position, and the position held by the holding device 10 is the C position.

Further, on the moving body 20, there is provided a reversing mechanism for rotating the suction arm 14 via the rotating shaft 15 so that the wafer 12 taken out as described above is rotated stepwise at the position B. There is. The detailed structure of the embodiment of the reversing mechanism will be described later with reference to FIG. Further, FIG. 7 also shows a feed mechanism that has the above-mentioned horizontal guide 18 and a movable body 20 that is provided so as to be capable of reciprocating along the horizontal guide 18, and that sends the wafer to each of A, B, and C positions. It will be described later based on this.

Reference numeral 14c designates a receiving portion, and the suction arm 14 which suctions and takes out the wafer 12 rotates by a predetermined angle,
When the suction surface of the suction arm 14 for sucking the wafer 12 becomes an inclined surface, the suction by the suction arm 14 is released so that the wafer 12 slides along the suction surface and moves by a small amount.
Is provided on the suction arm 14 so as to contact the outer circumferential side surface of the wafer 12 so as to match the outer circumferential shape of the wafer 12 and temporarily center the wafer 12 on the suction surface of the suction arm 14. In this embodiment, since the wafer 12 has a disk shape, the receiving portion 14c is formed in an arcuate step shape corresponding to the wafer 12.
By the way, it is preferable that the amount of movement of the wafer 12 on the suction surface is as small as possible in order to prevent abrasion of the surface of the wafer 12 due to friction. To this end, when the wafer 12 is sucked and taken out, the suction arm 14 may be moved so as to be as close as possible to the receiving portion 14c of the outer periphery of the wafer 12.

Reference numeral 22 denotes a centering mechanism, which has a positioning member 22b for laterally contacting the outer peripheral side surface of the wafer 12 sent to the holding position (C position) by the sending mechanism to center the wafer 12 at a predetermined position. The detailed configuration of the centering mechanism 22 will be described later with reference to FIG.

The operation of the loader having the above configuration will be described with reference to the configuration diagram of FIG. 1 and the schematic diagrams of FIGS. First, the tip portion 14a of the suction arm is advanced into the cassette 16. The cassette 16 is held by an elevating device (not shown) so that it can move up and down, and the elevating device lowers the cassette 16 by one pitch. As a result, the wafer 12 is received on the tip portion 14 a of the suction arm 14. Then, the suction arm 14 is connected to the suction port 14
The wafer 12 is vacuum-sucked and held via b. At this time, the upper surface that is the suction surface of the suction arm 14 is in contact with the polishing surface that is the lower surface of the wafer 12.

With the wafer 12 thus sucked, the suction mechanism 14 is moved to the intermediate position (position B) by the feeding mechanism as shown in FIGS. The cassette 16 remains on standby until the next wafer 12 is taken out.

Next, the suction arm 14 is rotated by a predetermined angle (30 degrees in this embodiment) by the reversing mechanism. As a result, the suction surface of the suction arm 14 for sucking the wafer 12 becomes an inclined surface. Wafer 1 by suction arm 14
When the vacuum sucking 2 is broken, the wafer 12 slides along the suction surface of the suction arm 14 and slightly moves, and the arcuate receiving portion 14c provided on the suction arm 14 contacts the outer peripheral side surface of the wafer 12. The wafer 12 is contacted and received so as to match the outer peripheral edge of the wafer 12. In order to prevent the wafer 12 from being scratched as much as possible, the amount of movement of the wafer 12 that slides on the suction surface of the suction arm 14 is set to be as small as possible. Then, the suction arm 14 sucks the wafer 12 again. As a result, the wafer 12 can be temporarily centered on the suction surface of the suction arm 14 as shown in FIG. By temporarily centering the wafer 12 in this manner, the wafer 12 is moved to the C position,
It can be supplied more reliably. That is, even if the wafer 12 is held in the cassette with some deviation,
The wafer 12 can be accurately fed to the holding position so that the holding device 10 can accurately hold the wafer 12.

By further rotating the suction arm 14 (150 degrees in this embodiment), the wafer 1 is moved so that the polishing surface of the wafer 12 is on the lower side as shown in FIG.
2 is inverted. At this time, since the suction arm 14 is formed in a U shape, the space for reversing the wafer 12 can be small. Therefore, the device can be downsized. Then, the suction mechanism 14 is moved by the feeding mechanism to supply the wafer 12 to the position C.

Next, the centering mechanism 22 is raised to the intermediate height position, and the wafer 12 is centered by the pair of positioning members 22b of the centering mechanism 22, as shown in FIG. At this time, the suction arm 1
The vacuum sucking the wafer 12 is broken by 4, and the wafer 12 is transferred from the suction arm 14 to the centering mechanism 22. The positioning member 22b is provided with a groove on the inner peripheral surface thereof, and the wafer 12 is inserted in the groove.
The wafer 12 is centered and held so that the outer peripheral portion of the wafer fits. At this time, since the wafer 12 is temporarily centered, the movement of the positioning member 22b can be small. Wafer 12
After the centering is performed, the centering mechanism 22 is lowered to return the suction arm 14 to the B position. Subsequently, the centering mechanism 22 is raised to the upper limit position, and the suction arm 14 is rotated 180 degrees in the reverse direction to return to the initial position.

Then, as shown in FIG. 6, the holding device 10
The wafer 12 is attracted by the. Next, the holding state of the wafer 12 by the centering mechanism 22 is released, and the centering mechanism 22 is lowered to the lower limit position. As a result, the wafer 12 is held by the holding device 10,
One cycle of the process of supplying the wafer 12 from the cassette 16 to the holding device 10 is completed. Therefore, according to this wafer supply device, the wafers 12 housed in the cassette 16 with one surface (polishing surface) facing upward
By not touching the polishing surface of the wafer,
It can be supplied to the holding device so that the polishing surface is protected and the other surface (sticking surface) faces upward.

Next, a concrete structure of each part will be described with reference to FIGS. FIG. 7 is a front view of this embodiment and shows a state in which the wafer taken out from the cassette 16 by the suction arm 14 is rotated by 90 degrees. Cassette 16
Is held in two stages on the vertical movement part 24 of the lifting device, and can be moved up and down at a predetermined pitch. Reference numeral 26 denotes a feeding mechanism, which is a movable body 20 movably provided in a horizontal direction along the horizontal guide 18, a ball screw 28 provided on the movable body 20 and screwed into a female screw portion, and the ball screw 28 is rotationally driven. It has a motor 30 for driving and a belt 32 for transmitting the driving force of the motor 30 to the ball screw 28. The feed mechanism is not limited to the above embodiment, but a combination of a motor and a belt, a combination of a motor and a rope, or a two-stage cylinder can be used.

Reference numeral 34 denotes a reversing mechanism, which is a rotary actuator 36 mounted on the moving body 20, and a rotary shaft 15 rotatably fitted in a bearing provided on the moving body 20 and having the suction arm 14 connected to one end thereof. , And the belt 3 for transmitting the driving force of the rotary actuator 36 to the rotary shaft 15.
8 The rotary actuator 36 of this embodiment
Is a vane-type swing actuator, which is a kind of cylinder device that rotates the output shaft in two stages by compressed air pressure. Reference numeral 40 denotes a sensor. The sensor 40 detects the rotation angle of the rotary actuator 36, and a controller (not shown) controls the rotary actuator 36.
Is controlled. Since the reversing mechanism 34 operates in two steps, as described above, the reversing mechanism 34 has a predetermined angle (30 in this embodiment).
It is possible to perform temporary centering when rotated. The reversing mechanism may be a combination of a direct-acting two-stage cylinder, which is a driving means using a fluid, and a crank mechanism, as in the above embodiment. Further, it goes without saying that a servo motor or a pulse motor, which is an electric driving means, can be used instead of the rotary actuator 36 or the like of the above embodiment.

As a method of temporarily centering the wafer, the suction arm 14 having a receiving portion that acts as a receiving member for receiving the wafer and also acts as an abutting member, and the reversing mechanism 34 are used. Instead of the method, another method may be used. For example, when the wafer is taken out by the suction arm, the suction of the wafer by the suction arm is released, and the wafer is received by the temporary receiving stand which is the receiving member, and the positioning member, which is the contact member, comes into contact with the outer peripheral side surface of the wafer from the side. It is also possible to adopt a method in which temporary centering is performed and the wafer is again sucked by the suction arm. The temporary centering mechanism performs centering by synchronously moving a plurality of positioning members that laterally contact the outer peripheral surface of the wafer toward the center, or one side of the outer peripheral surface of the wafer is contacted. It is possible to use, for example, a combination of a stopper and a positioning member that is driven by a cylinder device or the like and comes into contact with the other side of the outer peripheral side surface of the wafer for centering.

FIG. 8 is a plan view showing a specific embodiment of the centering mechanism 22. This centering mechanism 22
, Two arcuate members 23 formed by fixing the arcuate positioning member 22b to the mounting portion 22a are opposed to each other, and the pair of arcuate members 23 are provided so as to be movable toward and away from each other along the linear guide 42. . The positioning member 22b abuts the wafer 12 sent to the holding position (C position) by the sending mechanism 26 shown in FIG. Center. A groove portion is provided on the inner peripheral surface of the positioning member 22b, and the wafer 12 is centered so that the outer peripheral portion of the wafer 12 fits into the groove portion. As described above, the positioning member 22b only abuts on the outer peripheral portion of the wafer.
According to 2, it is possible to prevent rubbing the surface of the wafer 12 and scratching the surface.

The contact / separation mechanism for the pair of arcuate members 23 is
A rack 44 is fixed to each arcuate member 23 by protruding toward the inner side, and each rack 44 is meshed with a pinion gear 46 rotatably attached to the base body at a substantially central position of the centering mechanism 22. Therefore, when one arc-shaped member 23 is moved inward along the pair of linear guides 42, the other arc-shaped member 23 is also synchronized with the pair of linear guides 4 in synchronization with this.
2, the wafer 12 can be moved inward and the wafer 12 can be sandwiched and centered from both sides. Incidentally, 43 is a supporting member, which supports the pair of guides 42. Also,
The pair of arc-shaped members 23 move in the direction in which they are separated by the projection of the rod of the cylinder device 48, and are normally urged in the direction in which they approach each other by the spring 50. The biasing force of the spring 50 acts to constantly remove the backlash between the rack and the pinion gear. Further, when the wafer is centered, the rod of the cylinder device 48 is contracted. The drive means of the centering mechanism is not limited to the above embodiment, but a combination of a motor and a rack and pinion gear, a combination of a crank mechanism and a cylinder device, or a combination of a motor and a ball screw sensor can be used. can do.

Reference numeral 52 denotes a sensor, which is a notch (orientation flat or notch) provided on the outer peripheral portion of the wafer 12 for indicating the crystal axis of silicon.
Is provided to position the wafer 12 in the circumferential direction when the wafer 12 is held by the holding device 10.

FIG. 9 is a side view (including a sectional view) showing a specific example of the holding device 10. This holding device 10
Is attached to one end portion of the support member 54, and rotatably holds the wafer 12 on the lower surface side with the outer periphery thereof exposed. The holding device 10 includes a suction head member 6
0, a suction port 56 provided at the center thereof so as to communicate with a vacuum source (not shown), and an airtight member 58 that surrounds the suction port 56 in a circular shape. Therefore, the wafer 12 can be adsorbed and held by bringing the airtight member 58 into close contact with the surface of the wafer 12 and depressurizing the inside thereof. In this embodiment, a V-ring is used as the airtight member 58. This V-ring is molded by an elastic member such as synthetic rubber so that it can be suitably attached to the wafer 12, and the spatula-shaped portion 5 is formed to enhance its flexibility so as to enhance the adhesiveness to the wafer 12.
8a and has a substantially V-shaped cross-section.
The V-ring has a suction head member 60 so that the spatula portion 58 a is exposed on the surface of the suction head member 60.
It is mounted in the circular groove portion 60a provided along the outer periphery of the.

Further, the holding device 10 has a rotary drive device 62 for rotationally driving the suction head member 60 fixed to the upper surface side of the support member 54. The driving force of the rotation driving device 62 is transmitted to rotate the suction head member 60 via a speed reducer (not shown) or the like. Rotation shaft 6 with a reduction gear and suction head member 60 fixed to the lower end
1 is mounted on a bearing portion 64 mounted on the lower surface side of the tip portion of the support member 54 via a bearing, a seal member and the like. As the rotation driving device 62, a servo motor or a stepping motor whose rotation conditions can be easily controlled is used, and the suction head member 60 can be rotated in both forward and reverse directions at a desired rotation speed. The wafer 12 is rotated by the rotation mechanism that rotates the suction head member 60.
The parts to be polished on the outer peripheral portion can be sequentially fed so as to come into contact with a buff or the like which is a polishing member.

Next, an embodiment of a wafer discharging device (hereinafter referred to as an unloader) according to the present invention will be described. FIG. 10 is a plan view of an unloader that discharges the wafer 12 held by a holding device 10 that holds the wafer 12 on its upper surface and contacts the wafer 12 by suction. Reference numeral 70 denotes a holding device, which can approach the lower side of the wafer 12 held by the holding device 10 and hold a plurality of holding pieces 72a, 72b by laterally contacting the outer peripheral side surface of the wafer 12 to hold the wafer 12. Therefore, the holding device 70 can act as a holding means for receiving and holding the wafer 12 held by the holding device 10. The holding device 70 is rotatably provided in the horizontal plane by the turning of the turning part 74, and the Y position which is the receiving part position where the wafer 12 is transferred from the holding device 10 from the X position which is the origin position. , The wafer 12 can be unpinched and rotated to the Z position for ejecting the wafer 12.

Further, the turning portion 74 has a built-in turning mechanism, and the holding mechanism 70 can be turned so as to turn the wafer 12 by this turning mechanism. The rotation angle of the rotation mechanism can be set arbitrarily according to the discharge conditions, and in the present embodiment, it can be rotated so that the inclined surface of the shooter 78 and the wafer 12 surface are substantially parallel. The specific configurations of the holding device 70 and the rotating mechanism will be described later with reference to FIG.

Reference numeral 76 denotes a brush cleaning device, which reciprocally rotates about an axis 77 between an origin position and the Y position to clean the wafer 12 and the lower surface of the suction head member 60. Further, the shooter 78 has an inclined surface 78a, and as shown in FIG. 16, the inclined surface 78a receives the wafer 12 that has been released from the holding by the holding device 70 and dropped, and moves the wafer 12 therethrough. It is guided and stored in the cassette 16. It should be noted that the shooter 78 is provided so as to be vertically movable by an elevating device (not shown) so as to be positioned below when the brush cleaning device 76 receives the wafer 12 and is cleaning the wafer 12. Further, the cassette 16 is inclined adjacent to the shooter 78, and is held so as to be vertically movable at a predetermined pitch by an elevating device (not shown), and the portion in which the wafer 12 is stored is submerged. 79 is a water tank, 7
9a shows the water surface.

Regarding the unloader having the above configuration,
The operation will be described based on the configuration diagram (plan view) of FIG. 10, the schematic diagrams of FIGS. 11 to 13 and the side view of FIG. 16. Since the operation of the unloader has a close relationship with the operation of the brush cleaning device, it will be described together with the operation of the brush cleaning device. First, the brush cleaning device 76 is rotated to rotate the holding device 1.
Position directly below 0. Next, the brush cleaning device 76 is raised, the brush is rotated, and water is ejected to clean the lower surface (polishing surface) of the wafer 12. Then, the rotation of the brush and the ejection of water are stopped, and the brush cleaning device is lowered. Then, the brush cleaning device is turned to return to the original position.

Next, the holding device 70 is turned from the X position to the Y position. Then, the holding device 70 is mounted on the wafer 1 from directly below the wafer 12 held by the holding device.
2 is lifted to an intermediate height position capable of holding 2 and, as shown in FIG.
The wafer 12 is sandwiched by laterally contacting the outer peripheral side surface of the wafer 12. When the wafer 12 is thus held by the holding device 70, the holding of the wafer 12 by the holding device 10 is released, and the wafer 12 is received by the holding device 70.

Next, the holding device 70 is lowered to the initial position and further swung to the Z position. Then, the clamping device 7
0 is raised to a height position where the wafer 12 can be inverted,
The holding mechanism 70 is rotated by the rotating mechanism as shown in FIG. 12, and the wafer 12 held by the holding device 70 is rotated (see FIG. 13). In the present embodiment, as shown in FIG. 16, the wafer 12 is rotated until the inclination angle of the shooter 78 and the inclination angle of the wafer surface are substantially parallel.

Then, the holding device 70 is lowered to the intermediate height position, and the holding device 70 releases the holding of the wafer 12 in a state where the distance between the holding device 70 and the shooter 78 is reduced. As a result, the wafer 12 drops in a state of being tilted substantially parallel to the inclined surface of the shooter 78, so that the entire surface of the wafer 12 can be suitably dropped so as to contact the inclined surface of the shooter 78 substantially simultaneously. At this time, water is jetting from the inclined surface of the shooter 78, and the wafer 12 is received by the inclined surface of the shooter 78 without impact due to the resistance of the water, and is guided by the inclined surface of the shooter 78 to move (FIG. 13). (See arrow)
However, it is housed in the cassette 16 without shock due to the resistance of water. By the way, since the holding direction of the wafer 12 by the holding device 70 is substantially perpendicular to the direction in which the wafer 12 is ejected to the cassette 16, the holding pieces 72a, 72a.
b does not become an obstacle when ejecting the wafer 12, and the wafer 12 can be ejected smoothly. Note that, as shown in FIG. 10, if the clamping direction of the wafer 12 by the clamping device 70 and the ejection direction of the wafer 12 are set to intersect with each other, the clamping pieces 72a and 72b are actually the wafer 1
It does not become an obstacle when discharging 2, but it is desirable that they are orthogonal to each other optimally. Next, the clamping device 70 rotates,
The holding piece 72 returns to the upper side and is swung to X
It is returned to the position, further lowered and returned to the initial position.

Subsequently, the brush cleaning device 76 is swung to be positioned right below the holding device 10, the brush cleaning device 76 is raised, the brush is rotated, and water is ejected to adsorb the wafer adsorption surface of the adsorption head member 60. To wash. Then, the rotation of the brush is stopped, the brush cleaning device is lowered, and the brush cleaning device is turned to return to the original position.
As a result, one cycle of the discharging process for discharging the wafer 12 from the holding device 10 to the cassette 16 is completed. Therefore, according to this wafer discharge device, the wafer 12 whose one surface (bonding surface) is on the upper side and the bonding surface is sucked and held by the holding device 10 is the other surface (flange). The wafer 12 can be ejected so as to be stored in the cassette 16 so that the other surface faces upward while the other surface is protected by not contacting the other surface.

Next, a specific structure of the embodiment of the unloader will be described with reference to FIGS. 14 and 15. 14 is a plan view showing an embodiment of the unloader, and FIG. 15 is a plan view of FIG.
4 is a side view showing details of the holding device 70 of FIG. The holding device 70 is provided with a pair of holding pieces 72a and 72b. The pair of sandwiching pieces 72a and 72b are used for the wafer 12
The groove-shaped abutting portions 73a and 73b, which abut on the side, are arranged at a predetermined interval so as to face each other, and are rotatably provided in synchronization with each other. That is, as shown in FIG. 15, the sandwiching pieces 72a and 72b have the shafts 71a and 71b provided at their lower end portions so as to project in the horizontal direction.
The shaft 71a, 7
It can be rotated around 1b. A disc 82 is rotatably attached to a shaft 82a provided in the frame body 80 between the pair of holding pieces 72a and 72b. This disk 8
The attachment portion 83a near the outer periphery of 2 and one end of the connecting member 84a are rotatably connected, and the other end of the connecting member 84a and the holding piece 72a on the tip side are rotatably connected by a shaft 85a. There is. Similarly, the mounting portion 83b near the outer periphery of the disc 82 and one end of the connecting member 84b are rotatably connected, and the other end of the connecting member 84b and the holding piece 72b on the rear end side are rotated by a shaft 85b. It is movably connected. Therefore, when one of the sandwiching pieces rotates, the disk 82 rotates, and the other sandwiching piece can rotate in synchronization with the one sandwiching piece. In addition, in this embodiment, the material of the sandwiching pieces 72a and 72b is resin (Delrin), but not limited to Delrin, Teflon or urethane foam can be adopted. Further, a cloth is adhered to a portion of the main body formed of metal, which is in contact with the wafer 12, and the sandwiching piece 72 is formed.
It may be a or 72b.

Further, reference numeral 86 is a spring, and the mounting portion 8
3b and a projecting portion 80a that projects downward from the upper frame plate of the frame body portion 80. Therefore, the pair of sandwiching pieces 72a and 72b are urged by the spring 86 to rotate the disk 8
2 and the connecting members 84a and 84b, the contact portion 73 is always provided near the upper ends of the pair of sandwiching pieces 72a and 72b.
The a and 73b are urged in a direction of separating from each other. 88
Is a pressing rod, which is arranged so as to be in contact with the rear end side surface of the holding piece 72b on the rear end side and to be able to press the holding piece 72b. The pressing rod 88 is operated by the driving force of the cylinder device 90 as shown in FIG. Cylinder device 9
When the rod No. 0 contracts, the pressing rod 88 moves toward the front end of the holding device 70, presses and rotates the holding piece 72b on the rear end side, and in synchronization with this, the holding piece 72a on the front end side.
Is rotated. In this way, the pair of clamping pieces 72a,
The abutting portions 73a and 73b of the 72b are operated so as to come close to each other, and the wafer 12 can be held.

Reference numeral 91 denotes a rotating mechanism, which is the base plate 9
2 and a vertical shaft 96 for transmitting the power of the rotary actuator 94.
And a spiral gear mechanism 98 for converting the rotation of the vertical shaft 96 into the rotation of the horizontal shaft 99. One end of the horizontal shaft 99 is fixed to the frame body portion 80 of the holding device 70, and the driven side gear of the spiral gear mechanism 98 is provided at the other end. The starter gear of the spiral gear mechanism 98 provided at the upper end of the vertical shaft 96 meshes with the driven gear.
Further, a through hole is provided in the axis of the horizontal shaft 99,
The pressing rod 88 is inserted into the through hole. Then, according to the rotating mechanism 91, the holding device 70 can be rotated by the driving force of the rotary actuator 94. In this embodiment, the inclined surface of the shooter 78 and the wafer 12
Rotate so that the plane is substantially parallel. The rotation mechanism is not limited to the combination of the rotary actuator and the spiral gear mechanism as described above, but the combination of the motor and the spiral gear mechanism, the gear mechanism including the rack and the pinion gear, or the worm gear mechanism is appropriately adopted. it can.

Reference numeral 100 denotes a base arm, which is fixed to the base of the apparatus. A vertical bearing portion 102 is provided on the lower surface side of the tip portion of the base body arm 100. The vertical bearing portion 102 allows the turning portion 74 having the horizontal shaft 99 and the like built therein.
And a base plate 92 are connected to each other, and a support pipe 106 that supports the swivel portion 74 is rotatably and vertically rotatably supported. The vertical shaft 96 is inserted into a through hole penetrating the axis of the support pipe 106. The support pipe 106 is rotatably connected to the base plate 92.

A base plate 108 is fixed to the lower end of the vertical bearing 102, and a vertical movement cylinder 110 is arranged between the base plate 108 and the base plate 92. The driving force of the vertical movement cylinder 110 moves the base plate 92 up and down, and the holding device 70 can be moved up and down via the base plate 92, the support pipe 106, and the swivel portion 74. The vertical movement cylinder 11
Reference numeral 0 denotes a two-stage control cylinder, which can control the cylinder stroke in two stages. In this embodiment, the inside of the cylinder is divided into two to form two cylinder chambers,
A two-stage control cylinder is used in which a piston is fitted in each cylinder chamber and a cylinder rod is fixed by penetrating the two pistons. Therefore, according to the vertical movement cylinder of the present embodiment, the holding device 70 can be accurately positioned at three points in the height direction and can be easily controlled. Reference numeral 112 denotes a guide post, the lower end of which is fixed on the base plate 92 and the upper end of which is the base plate 108.
It is inserted into a through hole provided in, and guides the vertical movement of the revolving portion 74 and also acts as a detent.

Reference numeral 114 is a revolving cylinder, and the rod 11
The tip end of 4a is rotatably attached to the connecting piece 116 fixed to the lower end of the support pipe 106, and the cylinder tube 114b.
The rear end is pivotally mounted on the base plate 92. Further, the revolving cylinder 114 is a two-stage control cylinder and can control the cylinder stroke in two stages. In this embodiment, a two-stage control cylinder having the same structure as the above-mentioned vertical movement cylinder is used. Therefore, according to the swivel cylinder 114 of the present embodiment, the swivel portion 74 can be swung in the horizontal plane, and the holding device 70 can be accurately moved to each of the X, Y, and Z positions, and can be easily controlled. In addition, the holding device 70 and the swivel unit 74.
Needless to say, a motor, a gear mechanism, or the like can be used as a drive device for rotating the.

Next, another embodiment of the wafer discharging device will be described with reference to FIGS. This embodiment is an embodiment in which a suction device 130 is used as the holding means instead of the holding device 70. 17 is a side view and FIG. 18 is a plan view thereof. The wafer 12 vacuum-sucked by the suction device 130 is rotated and moved in the direction of arrow D by rotating the L-shaped arm 132 fixed to the tip of the suction device 130 about the shaft 134. . That is, the wafer 12 placed on the pedestal 136 can be substantially inverted and positioned on the shooter 138. In this way, the inclined surfaces of the wafer 12 and the shooter 138 are positioned substantially parallel to each other, and when the vacuum of the suction device 130 is broken in this state, the flow of water jetted onto the inclined surface of the shooter 138 and its inclination cause The wafer 12 is moved and stored in the cassette 16. The movement of the wafer 12 is preferably buffered by the resistance of water, so that the wafer 12 is preferably discharged without being damaged. In addition, the suction device 130 sucks the wafer 12 placed on the pedestal 136 by abutting the upper surface thereof. Then, since the suction device 130 is positioned on the lower surface side of the wafer 12 by being inverted, the shooter 138 is provided with the notch portion 138a so as not to interfere with the suction device 130. By the way, the wafer 12 is mounted on the pedestal 13
It is preferable to protect the polishing surface by setting the lower surface of the polishing surface on the polishing surface 6 to be the polishing surface and the upper surface of the shooting device 138 to be the polishing surface. The pedestal 136 is provided in a wet station for cleaning the wafer 12, and is formed so that cleaning water is ejected from the surface on which the wafer 12 is placed. Further, the pedestal 136 is provided with an elevator device (not shown) that can approach the wafer 12 held by the holding device 10 from the lower side and receive the wafer 12. 142 is a brush, and
The wafer 12 placed on the substrate 6 is reciprocated in the horizontal direction for cleaning.

Although the polishing apparatus for polishing the outer periphery of the wafer has been described above, the present invention is not limited to this and can be used as a wafer feeding / discharging apparatus in various wafer processing apparatuses. Although various preferred embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and it goes without saying that many modifications can be made without departing from the spirit of the invention. Is.

[0056]

According to the wafer supply apparatus of the present invention,
The wafer accommodated in the cassette so that one surface thereof faces downward is taken out by the suction member, the suction member is inverted by the reversing mechanism, and the wafer is sent to the holding position by the holding device by the feeding mechanism. Then, the positioning member of the centering mechanism comes into contact with the outer peripheral side surface of the wafer from the side to center and receive the wafer at a predetermined position. In this way, by not contacting the wafer stored in the cassette such that one surface is on the lower side with the other surface of the wafer, one surface is on the upper side while protecting the other surface. It has a remarkable effect that it can be supplied to the holding device. Further, according to the wafer discharging apparatus of the present invention, the holding means for receiving and holding the wafer can be rotated by the rotating mechanism such that the inclined surface of the shooter and the surface of the wafer are substantially parallel to each other. When the wafer rotated in this manner is released from the holding means, the entire surface of the wafer is suitably dropped so that the entire surface of the wafer contacts the inclined surface of the shooter at substantially the same time, and the wafer is suitably stored in the cassette via the shooter. It Therefore, it is possible to advantageously store the wafer held by the holding device so that one surface thereof faces downward in the cassette while protecting one surface of the wafer.

[Brief description of drawings]

FIG. 1 is a plan view showing an embodiment of a wafer supply apparatus according to the present invention.

FIG. 2 is a schematic explanatory view explaining the operation of the embodiment of FIG.

FIG. 3 is a schematic explanatory diagram illustrating an operation of the embodiment of FIG.

FIG. 4 is a schematic explanatory view explaining the operation of the embodiment of FIG.

5A and 5B are schematic explanatory diagrams illustrating the operation of the embodiment of FIG.

FIG. 6 is a schematic explanatory view explaining the operation of the embodiment of FIG.

FIG. 7 is a front view of the embodiment of FIG.

8 is a plan view showing details of a centering mechanism according to the embodiment of FIG. 1. FIG.

9 is a side view showing details of the holding device according to the embodiment of FIG. 1. FIG.

FIG. 10 is a plan view showing an embodiment of a wafer discharging device according to the present invention.

FIG. 11 is a schematic explanatory view explaining the operation of the embodiment in FIG.

FIG. 12 is a schematic explanatory view explaining the operation of the embodiment in FIG.

FIG. 13 is a schematic explanatory view explaining the operation of the embodiment in FIG.

FIG. 14 is a perspective view illustrating the embodiment of FIG.

15 is a side view showing details of the holding device in FIG. 14. FIG.

16 is a side view of the embodiment of FIG.

FIG. 17 is a side view showing another embodiment of the wafer discharging device according to the present invention.

FIG. 18 is a plan view of the embodiment of FIG.

FIG. 19 is a perspective view showing a conventional technique.

[Explanation of symbols]

 10 holding device 12 wafer 14 suction arm 14a tip part 14b suction port 14c receiving part 16 cassette 18 horizontal guide 20 moving body 22 centering mechanism 22b positioning member 26 feed mechanism 28 ball screw 30 motor 34 reversing mechanism 36 rotary actuator 70 clamping device 72a clamping piece 72b Clamping piece 74 Swiveling part 76 Brush cleaning device 78 Shooter 91 Rotating mechanism 130 Adsorption device 138 Shooter

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Internal reference number FI Technical indication H01L 21/304 321 H (72) Inventor Yamazaki ▲ Sadakichi 1650 Kiyono, Matsushiro-cho, Nagano-shi, Nagano Fujikoshi Machine Industry Co., Ltd.

Claims (10)

[Claims] 1. A wafer supply device for supplying the wafer to a holding device that adsorbs and holds the wafer by contacting the one surface of the wafer with the one surface of the wafer facing upward, and the one surface is a lower side. A suction member that comes into contact with the one surface of the wafer stored in the cassette and picks up the wafer by suction, and a reversing mechanism that rotates the suction member and inverts the wafer so that one surface is on the upper side. A feeding mechanism that moves the suction member and the reversing mechanism to feed the wafer to a holding position where the wafer is held by the holding device; A centering mechanism having a positioning member that abuts and centers the wafer at a predetermined position and receives the wafer. Apparatus. 2. When the suction member that suctions and picks up a wafer rotates by a predetermined angle and the suction surface of the suction member that sucks the wafer becomes an inclined surface, the suction by the suction member is released. The suction member is provided with a receiving portion that receives a wafer that moves slightly along the suction surface by contacting the outer peripheral side surface of the wafer and temporarily centers the wafer on the suction surface of the suction member. Claim 1
The wafer supply device described. 3. The wafer according to claim 2, wherein the wafer is disk-shaped, and the receiving portion provided on the suction member is formed in an arc shape so as to correspond to the outer peripheral shape of the wafer. Wafer supply device. 4. A wafer supply method for supplying a wafer to a holding device for adsorbing and holding the wafer, with one surface of the wafer facing upward and contacting the one surface of the wafer, wherein the one surface is a lower side. The suction member is brought into contact with the one surface of the wafer housed in the cassette so that the wafer is sucked and taken out, and the suction member is released and received by the receiving member. Contact the wafer laterally to temporarily center the wafer, and then again suck the wafer by the suction member, and in the suctioned state, rotate the suction member so that one surface of the wafer is on the upper side. And the wafer is sent to the holding position where the wafer is held by the holding device, and the centering machine is laterally attached to the outer peripheral side surface of the wafer sent to the holding position. A method of supplying a wafer, characterized in that a positioning member of a structure abuts to center the wafer at a predetermined position. 5. A wafer ejecting device for ejecting a wafer held by a holding device for adsorbing and holding the wafer, with one surface of the wafer facing upward and contacting the one surface, wherein the wafer is held by the holding device. Holding means for receiving and holding the wafer, and an inclined surface for guiding the wafer to be slid and stored in a cassette arranged obliquely when the holding of the wafer is released. And a rotation mechanism that rotates the holding means so that the inclined surface of the shooter and the surface of the wafer are substantially parallel to each other. 6. A wafer ejection device for ejecting a wafer held by a holding device that adsorbs and holds the wafer, with one surface of the wafer facing upward and contacting the one surface, wherein the wafer is held by the holding device. A clamping device that approaches from the lower side of the wafer and laterally abuts a plurality of clamping pieces on the outer peripheral side surface of the wafer to clamp the wafer, and when the clamping of the wafer by the clamping device is released, A shooter having an inclined surface for guiding the wafer to be slid and accommodated in a cassette arranged obliquely; and one surface of the wafer facing downward and one surface of the wafer and the shooter. A wafer ejecting device, comprising: a rotating mechanism that rotates the holding device so that the inclined surface of the wafer is substantially parallel to the inclined surface. 7. The wafer ejecting apparatus according to claim 6, wherein the wafer nipping direction of the nipping device is a direction substantially orthogonal to the direction in which the wafer is ejected to the cassette. 8. A wafer ejection device for ejecting a wafer held by a holding device that adsorbs and holds the wafer, with one surface of the wafer facing upward and contacting the one surface of the wafer. When the holding is released and the wafer is placed on the receiving portion, a suction device that approaches the wafer from above and suction-holds the wafer; and when the holding of the wafer by the suction device is released, the wafer is held by the suction device. A shooter having an inclined surface that guides it to be slid and stored in an inclined cassette, and one surface of the wafer with the one surface facing downward, and one surface of the wafer and the inclined surface of the shooter. And a rotating mechanism for rotating the suction device so that and are substantially parallel to each other. 9. A wafer feeding / discharging device comprising the wafer feeding device according to claim 1, 2 or 3 and the wafer discharging device according to claim 5, 6, 7 or 8. 10. A tilted surface of a shooter for receiving and holding a wafer by holding means, and a tilting surface of a shooter for guiding the wafer to be housed in an inclined cassette by a turning mechanism for turning the holding means. A method for ejecting a wafer, wherein the wafer is rotated in parallel, the holding by the holding means is released, and the wafer is slid along the inclined surface of the shooter and stored in a cassette.